Having had several offers to relocate to the Bay Area all I can really say is that almost nobody pays well enough to make it worthwhile. You can make $150k-200k in Seattle, Portland, Denver, Austin, etc. and work on some really interesting problems with marketplace leaders (often even for companies based in the Bay Area). You end up living like a king comparatively. You'd have to make at least 30-40% more than that in the Bay Area just to maintain a lateral quality of life.

Having now screened over 300 candidates for openings on my team, the overwhelming majority of them being people already in the Bay Area, about the only thing I can say is that with all the easy money sloshing around the economy there it's just way, waaaaaaay to easy to be a terrible engineer and still maintain being a highly paid "professional". Most of the people I screen/interview are advanced-IDE users at best or simply framework operators (i.e. they have no idea how the things even work that they're claiming to be experts in).

Sure there are a lot of bright folks too (law of averages and all that), but it's depressing to see what people are getting paid to do glorified web scripting or whose entire job function could be replaced with 50-lines of Bash.