So many variables on this, I could only give you a range....$110-200 per Sf. I built spec homes that cost me around $155 per sf, when I paid $60,000 for lot. The finish out was travertine and carpet floors, Granite counters, stone and stucco (20-80%) exterior. That would include the builder's fee as well. All homes were built in Lake Travis area.
If you want to discuss further, feel free to contact me. Like I said, so many variables on this it's impossible to narrow it down more than the range I gave you without a lot more information.