First thing, are you sure the place will be built and move in ready before your lease is up? If not, can you get a month to month lease from your landlord. Even if you are sure it will be done, talk to the landlord anyway. Problems crop up and closing dates change.

No, you don't need an agent for picking out cabinets and such, there is no price bargaining there. What the carpet, cabinets, faucets etc. cost is a set price when you buy into a community. They are not going to sell you the same carpet the next door bought for less money.

Also be very careful in bringing her along. If you do, make it 100% clear that it is only because you like her company. If she thinks she is making commision off of going with you, you will have trouble.

Asking for discounts or if there are "packages" of options (like if you buy the nicer cabinets you also get the floors upgraded for free) instead of paying for things a la carte is fine. There is nothing wrong in asking politely.

And the saleslady may be very nice, but it's her job to be nice to prospective buyers. She's NOT your friend, she does not know you. And she likely gets a commission if she talks you into buying expensive upgrades. You need to think critically about any offers she gives you. Ask yourself if they really make financial sense.

It's not unreasonable to try to bargain, and it's not an insult to the saleslady you were working with. It's all about HOW you do it.

One other thing...taking along a "part time" broker might not be a good idea. Will this person think they are acting as your agent? If they are you may have to pay them. Money & friends should never mix!