Used Record Shows in San Francisco Bay Area...

Rasputin also has a store in Fremont, at 880 and Mowry, in case you're in the south bay. There's loads of used LPs for 50cents each, but be prepared to spend some time as the majority are thrashed. They also have used CDs.
I've had about 30-40 LPs off them for less than $20, and this has allowed me to sample several new (old) bands and composers. I've also found a few classical boxed sets in perfect condition for $2-3 each.

Check out The Record Man in Redwood City on El Camino Real. Great Selection.

Forgot to mention, the Anolog room in San Jose. Someone had mention another store in the San Jose area but can't remember the name, anybody know?

The Analog Room is all new vinyl, I beleive.

No, the Analog Room has new and used vinyl. Prices are high, but quality good. Credit cards accepted but, without saying more, I advise cash.

Note: If you are one those people who does not like the smell of cigars or feels that they will shorten their lives through brief exposure to second-hand smoke, try another location.