I lived with 3 roommates to save money, I sold my car, you won't get stabbed anywhere in SF (so live in the sketchy area it'll get nicer each year). My rent was $1,200 a month, a lucky find.
Now don't get me wrong I hated living there, no girls, homelessness everywhere smelled like garbage, and a self-obsession that pretended to be health-minded but was really wealth-minded ($9 juice OMG).
But the earning power change by having lived there is night and day. To have companies people have heard of on your resume goes such a long way.