It depends on your location. If the painter is supplying all the materials, doing the prep work and patching, I'm going with $800.00 per day. I'm in MA.

It’s hard to tell without pix and/or your location. That’s a lot of money, but also a lot of prep work so you’re smart to get another quote or 2. I used to try to get three quotes and decide. Nowadays it’s harder to find people here, so I may choose from two quotes.

He will use BM aura. the hallway might be 100 square feet i think. The walls are ventian plaster and burnished so thats why skim

coating is needed. I live in Oak Brook, Chicago suburb.

Sometimes they jack up the price because they dont want to deal with small jobs, but if the customer is willing to pay a premium they'll do it. I was astounded when in another post, the OP had been given a quote of $2,000 for painting a door and trim around it. Even if massive sanding and wood repair that's still over the top imho.

In your case though the resurfacing of the plaster adds considerable time/complexity. You might ask them to clarify their quote - certainly not to complain, but in a friendly way just to understand what goes into this job. Just to know, and then also if you get more quotes you can be comparing apples to apples. Your heading says $7,000 for "painting cost," but there's more to it than just the painting.

You need to not think of this as a paint job. It is a resurfacing job. There is a lot involved and probably multiple trips on different days while the coatings dry and harden. Yes, always get three quotes. (Though good luck during COVID - maybe 2 is more realistic.) Make sure both quotes are compairing apples to apples and include the same scope of work.

Ok. yes he gave me a quote breakdown .

yes, the room walls are a bit complicated. so i guess of we need to get it done we should go with a good company rather than throw out money to just anyone , even if we get lower quote. we have one guy coming this week recommended by our old realtor. we will see how it goes.

the other rooms are also venetian plaster but he is saying he can paint over them without skim coat and they would look fine. his regular room

painting is about 2-3x the other quotes. but he is currently doing a 6.2 million condo in gold coast so i can at least trust he will do a good job !

Seems very high to me. I understand you have the expensive house in an expensive neighborhood premium but that is a lot of money. Is there anything unusual about your house or lifestyle which would increase prices? My first thought is to ask about the proposed schedule and who will be doing the work and find out when he is available to start.
The proposed schedule is a method to get an estimate of the depth of prep work he is expecting to do. If he thinks this is a 3 day job, then he doesn't want the work but would be willing to if you are desperate enough to pay that much. If he says two weeks full time, he is planning to be very detailed and either works quite slowly or is absolutely meticulous which might be a higher standard than you wish. Asking about the crew is another route to finding out how much prep work he plans. On a skim coat job of that size, I would expect a helper to mix mud and run buckets. If he is availabe to start whenever you want he is either going to give your high dollar job top priority or pricing high enough he doesn't have to work full time.
What materials is he using? I don't know about covering burnished venetian plaster but it probaby needs a bonding primer to stick. At that price he might be using real plaster which would contribute to the expensive quote.  
If you want a good feel for the quote then take some pictures with you and go chat with the staff of your local paint store.  There is probably a JC Licht store relatively close and they carry high quality products. Chat with the staff and find out if they know anyone familiar with venetian plaster and see if they have any business cards or referrals.  If you want to find someone for another quote, show up at the store at opening time or closing time and observe.

Seems high to me too...... I paid $10,500 CAD for all painting + popcorn ceiling removal in two bedrooms, hallway, living/dining and bathroom -- total about 1200sqft. This was in Vancouver Canada. It was a big job and took them about 10 days.

Is the living room and family room on the quote the 100 sqft small hall your are speaking of? Or is it the Foyer with the doors and 2 windows? Or is that whole thing the total of 875?

he gave me quote for each room separately. ( bedroom with a small bedroom hallway, family room, living room, foyer, stairs, main floor hallway)

$875 is only for the entry door and window trim for the two narrow windows beside the door.

master bedroom which is the most complicated ( including the bedroom hallway) is broken down into 3 payments, the total of which is $7000.

total for whole project of above areas is $18,000.

Ok, thanks for the clarification :) So 7000 for the bedroom and hall, 9000 for the living room and family room then. What sizes are those rooms?

You are in Oak Brook, and that is one of the more expensive burbs of the area. That might play a factor into it. And if they are top notch they probably can command a more premium price. I'm not sure if those are enough to make the price seem more justified.

Yes the rooms are a decent size. Thats what i am trying to figure out if it would be worth to pay 2-3x more .

i do know that we got our dining room done for much lower price ($1200 for removing crown moulding, skim coat, paneling and paint ) but of course the low price showed. it wasnt done neatly. they didnt cover up the things properly . and they didnt leave the floor spotless. And then never showed up after taking the money. was supposed to come back and fix the flaws.

theres a saying in my language which is something like :

spend more and cry once

or spend less and cry again and again.

lol!

just dont know what is the upper limit of spending .

There is quite a bit of distance between your $1,200 painters and an $18,000 project. For that much money, I would go to the paint store and ask for the names of a couple higher end painters. I think you could find someone significantly cheaper without getting on the wrong side of the price versus quality balance.   
Before spending that much money on a paint job, I would be looking to see some of his work in person and talk with a couple recent clients. You would hate to pay that much money and still have issues with the workmanship or the contractor's business practices!

Why would a painter just paint over it instead of sanding it off?

@lyndee lee I read reviews and he is well known to jclicht the paint store which sells all the benjamin moore and other high end paints. in fact jclicht has their brochure printed with his name for his clients that he showed me.

regardless, i already told him and he himself suggested that i should first have one room done and see how it will look , as paint has to go over venetian plaster in living room and family room. This is a tricky job thats why i m willing to spend money.

living room is $2100 and would give us an idea if neatly done work is that much better to look at. If it does make a big difference , then I wouldnt feel bad . and if it doesnt its not 18000 i have put in.

@loobab master bedroom must be skim coated as one of the walls is badly done.

the rest of the rooms have a very nice venetian plaster on the walls. i dont mind keeping it. To skim coat it is a lot of work, creates dust and is expensive. so i would like to first see how it looks with just the paint.

$18K. That's a used car. As others have recommended, definitely get other quotes.

My $.02 Are you willing to get a quote to replace and finish the wallboard?

is "he" on-sight, working with a crew or is he estimating and sending in a crew to do the work? My experience - and just my experience- is the person estimating the job is experienced and talks projected detail but the crew is young, inexperienced, and in and out because time is money. Much is lost in a lack of communication/expectation skill/training. The estimator doesnt return to the job site to direct and monitor progress.

i had work done - wallpaper off, patching and prep walks for painting - I'm now ready to paint and called to ask what products were used, I.e. sealer. There's no record though I did learn after the fact that plastic wood fill was used on wood destined to be stained. Plastic doesn't accept stain.

I'd ask for a more detailed estimate.

He sounds like a high end painter and if you have the financial resources to hire him, you will probaby be pleased with the outcome.  Everyone has their own idea of what level of work they are willing to buy for their home. On a scale of 1 to 100, I shoot for 80 to 85 with my work; going lower I won't be proud to put my name on it and going higher will take a lot more effort for a small increase in quality.  I need a nicely finished project, not a perfect one that doesn't get finished.  
I did look over the estimate and noticed that the work said prime and paint plaster skim coat and real plaster is more money than drywall mud.  Several years ago, I was chatting with a plasterer in the NW suburbs and his labor rate was about triple that of a typical drywall finisher. He said he was aways busy and was selective with the jobs he did take on.  
I hope you will share some pictures of your finished room

Living room is 2100, so that means the family room is 7000 like the bedroom/hall is 7000? I assume the living room and family room estimates are seperate? Can you give us those estimates like you did with the bedroom estimate please?

First no where in that contract does it mention the type of finishe the walls will be. If budget is the issue then I would prefer my LR to be a smooth skim coat before the bedroom . The contract does not specify what paint is used either . a newly plaster wall will need IMO 2 coats of primer and the finish needs to be smooth and that needs to be spelled out in the contract .

@Lyndee Lee here are the other estimates.

i dont want to discuss with him yet as i am getting a second quote tomorrow.

@Patricia Colwell Consulting he told me they only use Benjamin Moore aura. it does state that on the bottom too, and all rooms one coat prime, 2 coats paint

the only reason we decided to go with bedroom first is that it needs to be done vs wanting it to be done. because we took off the curtain rod and behind it the wall needs to be repainted anyway. also one wall is improperly done to begin with. and because venetian plaster is complicated, if anything goes wrong, its still the bedroom , not the living or family room.

like i said i would be ok without skim coat everywhere else ( i just dont like my existing paint color) if he can paint over venetian plaster and it turns out ok, i m fine with it.

we did have same textured wall in dining room and we got that skim coated , but that was much less expensive.

if i end up getting every room skim coated it would be around $ 6000 per room.

I got a second quote, which is more in line with what i have been quoted by other painters.

he doesnt seem an expert. he said he would just paint over our bedroom walls, and we know thats not going to look right. I think we decided that complicated rooms like family room, LR and bedroom we will get done by the more expensive one. and the rest of the house by the other.

i am going to call and ask if he will be on site, guarantees etc.

anything else i should ask before i sign the contract?

Ask about scheduling and be sure they will work mostly full days every work day until finished. Good painters won't leave you with your house torn up and go do another project or take a vacation but confirmimg this never hurts! 

If you choose to have the second guy do only part of the job, he may charge you a somewhat higher price. There is some uncertainty in every job and on a big job the over estimated portions tend to balance out the under estimates. For example, painting doors for less than $80 each seems low to me.  Also there is the job administration and setup which is required for each project and his set of prices is probably based on doing all the work at the same time. There is overlap between rooms when doing more than one space; patching two spaces isn't double the work when the tools and materials are already at hand. If you discussed this already with the painter, then he won't be surprised otherwise be prepared to reevaluate the prices.

Ok I asked these questions and were satisfied . Also looked up ratings and read reviews on yelp, Google and Angi list. They were excellent. We asked him if he could give us estimate without baseboards. He came over again today to go over the details once more. He said baseboards should be done together . He suggests painting the ceiling and crown moulding as well. Instead of a Lower estimate , it seems more work has been added and the next quote would be higher . He will give that next week.

We also got one more quote from my electricians neighbor , who also had excellent reviews .

Here is his estimate : quoted differently, so not exactly exact comparison. but once ypu look at th details and work it out , its not v different .

You are doing a good job of getting estimates and discussing concerns with multiple contractors. If you are getting two high end painters with similar prices, either will likely do a good job. 
Definitely get all the surfaces painted. Many people think they can save money by not painting the ceilings but the new paint job on the walls make the ceiling look awful by comparison.  There is nothing like sparkling clean and shiny new work to highlight everything which hasn't been touched.

Demo the walls and do new drywall.

Verbo-

Do you suggest demo-ing the walls and putting up new dry wall because it is more cost effective than either of the two alternatives discussed above, 1. sanding off the current venetian plaster or 2. skim-coating it?

Or because it will just give a more perfectly smooth surface?

Or both?