Well, in our area Carrara marble is the same price as a mid-priced granite, so cost doesn't have to be a factor. We did our perimeter in marble. I read all the warnings about the horrible etching and staining that were my future if I chose marble, and I tried, I really tried to love something else. NOTHING else had that look and feel. Dh realized I'd never be happy if I didn't get it, so he grudgingly agreed. He told me, though, that it was a counter, and he wasn't going to go beyond his normal wiping up spills and using a cutting board like he had always done. And he doesn't. And it is fine. My 9 year old dd and 12 year old ds mostly use the walnut island or the kitchen table for eating, homework and crafts. I have trained them to always put dishes in the DW or sink, not on the counter. They are doing great...as are my counters! I love them everyday...the slight extra bit of carefulness I use is absolutely worth it to me. And honestly, if you are a fairly clean and tidy person to begin with...you won't find it difficult. I mean, if you are prone to leaving dried sauces and food on your counters for extended periods, I'd say get something else, but I think most TKO people would do fine with marble! :)

Like you, I always went back to marble in my counter top search. It's my first love. Nothing will ever change my love for its beauty! That being said, I did not get it. I chickened out. Price was the same as the granite we chose, so it was just my choice to walk away from marble. Since installing new counter tops, I have had days with regret, and days I am glad. Here's why...

My island top is Mahogany, which is somewhat of a softer wood. It has scratches in it, light ones... you can't feel them with your hand, but you can see then in the sunlight or when you are down at the right angle. Nothing awful by any means. I can live with it. So, I have to think this qualifies me now as one able to live with marble :)

Then, there are days like this past week....my kids cut lemons themselves, just to see everyone pucker, left strawberry jam sitting on the counter for hours while I was away....those are the times I wonder how marble would have held up.

Unfortunately, no one around me has marble to see it or ask all my questions :)

I figured marble was too much work to keep nice on a primary counter so I used something neutral and invincible on the counter and a slab of marble as a backsplash (as well as a baking area chunk).

If you put your marble in a highly visible spot like behind the stove, it's the best of both worlds--all the pretty without the stress.

I also did marble perimeter and a contrasting island (Cambrian Black granite). Having one work area with no worries may help temper your concerns. I told my two teen boys to do they messy work and lemon juice squeezing there, but I also had a bottle of lemon juice spill on the marble next to the stove. We all lived -- counter too. Wiped it up quickly and didn't notice any change.

There is a concurrent thread right now that addresses this question in great detail, plus it includes links to two other photo-laden threads that breezy provided. I think the three threads constitute a definitive discussion of the pros and cons of marble. Should answer all the questions you raise.

Breezygirl--question

We love our marble.

We have Callacatta Gold in our Summer home. It's the only counter surface in the kitchen (perimeter and peninsula). We sealed it once and there is some etching, but I only notice it in direct sunlight. Because it's our Summer place it doesn't get the year round abuse, however, when we're there it probably gets more day to day wear than our year round place. For example, there's no school so the kids are strolling in and out of the house 7 days a week and we eat most meals at home. We also entertain much more there, and have frequent overnight (if not week) guests. I've never given instructions to guests or anyone else and have had only had one issue - that was when someone left a bottle of red wine out all night. It was screwtop so I didn't even notice it had been opened. When I discovered it the next morning, I was able to get rid of it and you'd never know it happened.

Also, we're going to be building a new house and my husband said he definitely wants to put in marble because he loves it so much (yay!). In discussing marble with someone they mentioned etching and I said "yes, we have some etching". DH looked at me and said "We do?". :-) Anyhow, we love it and will do it again. My kids are three and six (girl and a boy). My three year old is a complete disaster when she eats pasta with red sauce, by the way and I have never stressed over it. Now on the other hand, this house is the first place where I've had stainless appliances and they drive me crazy! I feel like I am constantly cleaning up fingerprints. So go figure? For me, marble? No hassle. Stainless fridge and dw? Drives me freaking crazy! I will do anything to have a paneled DW and fridge in our new build :-)
So that's my experience and I hope it helps you and anyone else considering marble.