This analysis is very low quality. Engineers move to the bay area not for salaries, but for equity and RSUs. It's not unusual to make your salary again in RSUs, which are usually not that risky. Equity is a mixed ball, however. But these two factors are the unique element in the Bay area, and why you should move there. If you are an engineer in the bay area without loads of equity or RSUs, you're getting ripped off.