They’ll show you the options before you sign a contract, you just have to ask the sales associate. I’m sure some are tougher about it than others, but I’m sure you can get it if you insist.

I’m not surprised they refused you at the design center though.

Also, the options they’ll show you are strictly for builder options, which is pretty much anything you can do or add to the house with the notable exception of flooring, window coverings, and most landscaping. They’re not trying to do anything devious by keeping those separate, it’s more a matter of too many choices. I’m sure you could get prices for those as well before signing a contract (or at least make it a contingency).