I would be all for seeing a permanent on-road nitro friendly track in Northern California, but I can see where rctrackman is coming from. Real estate up here is becoming a joke. I'm not sure how the housing market is in the bay area (I understand it's finally starting to improve), but Sacramento, Roseville, and even my home town area of Yuba City is getting pretty costly. Still I think much of it's cheaper than the bay area.
Speaking of the bay area, what about Petaluma/Santa Rosa or some other place in Napa or Sonoma County? That seems like it would be a decent location (but once again, I have no idea what real estate is like there).
I'd say if you couldn't do the San Francisco area, I would try the north bay. It seems like it's a short enough shot from many points. You could attract peeps from SF, East Bay, Oakland/Berkeley, Sacramento, Vallejo, Fairfield and many other areas. It's a good hub without having to deal with San Francisco proper.
Cheers!
Chris