Seriously, half a million in Vacaville? I bet you work in the bay. You do realize gas isn’t going to get much cheaper, right?
Plus the 80 in rush hour is worse than the 15. To me there really isn’t a price at which homes in far flung exurbs are worth purchasing, unless you make your living in the area.
I for one wouldn’t buy in any area where I didn’t work fairly close by. Thats one of the ideas that I personally feel is going to be done away with in the coming storm, that being long commutes. That and we aren’t anywhere near bottom yet, even in and especially the outer exurbs.
If you like the place and can comfortably afford then its merely a matter of whether you are willing to make the commute. However I’d be damned sure you can actually afford it. When interest rates go up, you won’t be able to sell it for what you owe.