It seems fine for what you are adding. If you sell and other homes in the area have less square footage you will be ahead. 9’ ceilings are a big plus and will add resale value. The smaller items will probably help you sell quicker. Most buyers calculate price per sq ft. So figure out by discussing with real estate agents familiar with this area, whether these improvements would help in resale and what recovery could you expect. Adding sq ft typically brings most return. If you sell in 7 years or less you probably won’t recover small adders because their “life” is nearly over. Good luck. Make it enjoyable for you now.

Explore sites like realtor.com, and see what comparable houses in your neighborhood are selling for, preferably houses on your street or around the corner. Look at price per square foot, number of bedrooms and bathrooms, garage stalls, etc. Find as many houses as you can, that are similar to yours, within 2-3 miles.

If your house is more than your local comps, you may be responsible for the extra money out of pocket, assuming you are financing. You may or may not get that money back when you sell. Tread carefully.

I will say that there are things on your list that I would remove, personally. Production/tract builders often offer junk in upgrades at awfully inflated prices.

For example, with our first production house, my husband and I thought we were doing well by upgrading the carpet by 4 levels. A few years later, the house flooded, so we went to a flooring place to look at our options. The flooring guy flat out said, "We don't carry anything of this low quality; our 'basic' is a lot better than what you had." Shocked. So, with our second tract house, we didn't bother upgrading the carpet at all, and will soon replace it with something way nicer.

the 9 foot ceilings and loft seem like good ideas. The ceiling fan price is reasonable and if you use it that’s a nice thing. Also the water softener but compare prices for installing after.

For the rest it’s your preference I think. In our market 30k would not be crazy but you won’t get back the value of, say, cultured marble vanity tops, in resale.

one thing I wouldn’t do is a glass pantry. Food liked the dark better than light.

10% hardly seems excessive, especially considering how much you'll enjoy them and the value they add.

No one else can tell whether these things are worth the money to you. If you live in the house for 10 years the difference will be about ten dollars a day. You might even get some of it back when you sell, but I would never let resale value influence such a decision. (other people are clearly driven by potential resale value, I don't get it, but people are different in what they need and value) Higher ceilings would be worth it for me in a heartbeat, but I can't tell you what you might value.

Price out an item you would like at a store/website and compare it to the upgrade price. If you can replace it yourself you may find it is cheaper to do it yourself later (Ex. faucet, bathroom counter seem like easy DIY fixes). Post by One Devoted Dame shows first hand experience with builder material.
But if you like the upgrades provided, the move-in ready has appeal as well.

^Don't just price out the cost of the item though. Be sure to include the installation and the cost to remove and haul away the builder standard item that was installed if you don't plan to install the upgraded finishes yourself. Some upgrades may be cheaper to do yourself later, and you may get a better quality product later. In other cases you may be spending more to get the exact thing. If you are unsure about the worth of some of the upgrades, ask your builder for actual product data to be able to compare.

Not knowing what house values are like in your area, I would guess that you will get back 300% on your extra square footage, as the builder is only charging you $30 per square foot for the added area. The 9' ceilings would be definite value added too, especially as higher first floor ceilings continue to be considered a standard across the country. The rest of the upgrades add up to only 16-17k That amounts to only 4% of the final adjusted cost of your house. If you feel like they are worthwhile to you, and the either the utility or aesthetic satisfaction with your home, I would go for them..

If you sell and other homes in the area have less square footage you will be ahead.

Yes you'll be ahead in the sense that if you need to sell you'll sell faster but as I said above, the largest house in the neighborhood doesn't necessarily sell for more money. It just sells faster IF it's priced similarly to the other homes.

All real estate is local. When I work with clients building new homes, one important thing I help them navigate is cash flow after closing. Leaving a lot of items you want to after closing runs into two main problems. Will they have adequate liquid funds to buy these items cash. Most are strapped financially after closing so these items get delayed quite a bit. Second, large items like flooring changes become daunting after moving in because they are so disruptive to daily living. And more expensive than estimated originally. So, review your list. Of course, 9’ ceilings are a must up front design consideration. Do that. Flooring might be next biggest expense and very disruptive once moved in. Lighting is very important to getting everything looking great. Get as much of that in as possible. A chandelier or two could wait but installation is sometimes harder than you think. Getting electrician out is difficult for small jobs. And remember your builder is warranty provider so keep that in mind. Installing large fixtures will be costly. Depending on your geographic location, can run from $125 per light to in excess of $500 if scaffolding is needed etc. so think about that. It all boils down to a financial and logistic decision in the final analysis.

Overall 10% is really not bad...

250 sq ft loft to the already 2200 sq feet finished space (3200 including unfinished). This is an extra $7600 for this space.

7600 : 250 = $30/sq ft = YES in my book.

9ft cieling $5664

A little expensive but Yes.

Water softener $2512

No, you do not know what water treatment you need, and the builder is going to install some really cheap and bad equipment.

Lighting package $1000

You will regret this. Tract builder lighting packages aren't very good. And they look like a tract builder. But go for it if you can not replace the lights and need an electrician.

Carpet $2200 - NO

cpartist and BT and the others are right about thinking through each individual selection and its benefit to you. The items that have to be added through the builder if you are going to get them make sense (9 ft ceilings make sense for example). The loft is very personal. In some markets/neighborhoods the loft is expected and in others it is a waste of space because the access is awkward (small spiral stair for example). This is a decision only you can make. CP nailed it in her post.

Lighting: You didn't say what the lighting package is at all - wiring or fixtures. I assume the builder is selling you a 'better' grade of light fixture. That is the worst possible way to buy lighting - through the builder. It is the most expensive method with the fewest selections and most are referred to as builder basic, even with their upgrade choices. So, if you still have the ability to change, don't go through the builder, do the fixtures afterward. Naturally, if you are talking about wiring and not fixtures, then do it through the builder for limited lighting choices. BTW, you can get better light fixtures anywhere including CL, OfferUp, FB Marketplace, lighting outlets. Better choices. Less expensive. Take your time.

Carpet: No, as explained up thread a couple of times. Get the standard and take your time selecting the right flooring to go in when the carpet wears out - which will be shortly no matter which builder upgrade you select.

Water softener: Get the specs the builder is supplying. Compare to outside vendors then decide which way you want to go.

I would get builder standard hardware and faucets and make those changes after closing.

Don't know if the island is worthwhile or if it fits. You didn't post your plan or island details.

Go through each individual item - do you need it? You could probably easily shave off $10k and still have a wonderful home. Not spending that $10k in your mortgage could save you an additional $17k in your mortgage over 30 years. JMO.

Yes.

No.

Perhaps you should ask someone local that knows you and knows the details of the things you are asking about and knows what a Full siding beams is.