As someone who just moved from Portland OR to the Bay Area in order to take a "corporate" engineering job in SF (and got a >40% raise in the process) I can say with confidence that the cost of living here, even outside the city (specifically Berkeley for me) is easily 2.5x what is was back in PDX, even with a 60 minute commute and meals comped at the office.

It's not just housing (which costs easily 2x what it does in or near any 2nd-tier tech city) - transportation, food, and mundane but pleasant things like pints of microbrew and movie tickets are way more expensive, too.