The first mistake as a potential custom home buyer, is to "not" know what you want in a home. You must do your homework first. If you tell the designer I want this picture in the magazine, well that will likely cost you. Its not like going to the restaurant, where you see the item and the price. Its rather like the mystery meat menu. Discover what you want, and approximate price before you go to selecting a builder. REMEMBER...their time is money also... if they have to do therapy on you to figure out what you "really" want... it will cost you :).