Cag038, It depends. I have built two custom homes for my own use - one in San Diego and one in Big Bear. They were both very nice homes with top notch building materials and upgrades. The price per square foot to build can vary from $100 a square foot to $300 square foot and higher. It all depends on what you want the quality of the home to be and the quality of upgrades. Contact the San Diego Building Industry Association. BIA. I have worked with them in the past at charity events. http://www.biasandiego.org/ Good Luck!