It's usually the same issues everywhere. How cheap can you get land and how cheap is it to develop in that locality? If you can find a good deal on land and can cash build, then you're golden. If you have to buy land over-market and pay interest for 10 - 12 months, not so much. Someone can tell you all day that they can build at $x/sqft but are they including the land purchase, the dirt and dozer work, builder's risk, upfront and long-term carrying costs and etc? Who knows. OSB and dimensional lumber are on the rise again. Everything else doubled and tripled in price while everyone was rubber-necking lumber earlier this year too.
@Jay Hinrichs, I'd love to see some sort of redacted, categorized cost report, just to see what you're paying for labor for bulk projects. I can't come close to building a house for $80/sqft (in 2015 maybe), and that's in a country bedroom town in SE Texas, with no garages, no carport and minimal porches.