There are a lot of startups in Salt Lake, UT. Billboards everywhere looking for devs. I really am surprised it never gets mentioned on posts like this. Salt lake area cost if living is about the same as Austin I believe l, but based on the fact that it isn't as well known that it is truly a tech hub, cost probably won't rise nearly as quickly as the other places.
It has recently been called *Silicon Slopes" by Google (when they installed Google fiber), if that's not enough proof idk what is. Also Utah might be the first state to have Google fiber in two different cities. (Provo, and talk of Salt lake)