Past appreciation rates are not going to be helpful even if you find good data. To answer your question, no, you most definitely CANNOT simply carry thouse appreciation rates forward. Past performance is no guarantee of future results. If you have been reading this blog for months then you know that the wrong idea that past appreciation rates will continue indefinitely was a big source of fuel for the housing bubble.

If you want to stay in SD, why would you leave? IMHO life is too short to live somewhere you like less just to save a few bucks. Decide where you want to live first, then decide whether to rent or buy.