The cost can vary greatly depending on the location of the lot. Believe it or not, everyone involved will charge you more to build in WaterColor than in some unheard of s/d. Also, some areas may required a specifically approved architect, thereby costing even more money.
If we are talking about a lot in an unnamed s/d, you can expect a cost of $130/sf for a medium-low appointed home. Perhaps going with a cheap (quantity rather the quality) entry level home, you can lower your costs to maybe $110/sf. If you are thinking about being your own contractor to same some money, I would certainly urge you to reconsider if you are doing so because of money. When your subs don't show or worse, walk off the sight or overcharge you; when you can no longer sleep at night; or when a year has passed and you are still building -- Then, you will be wondering if you saved any costs at all.
I mention the low to medium cost level only because, as you know, the sky is the limit.