Used LPs in San Francisco area


I just bought a new turntable (just a p1 with an Ortofon 2m Blue) and I'm enjoying the 150 or so LPs I still have from my younger days. I'm looking to cost effectively add to my collection. I went to Amoeba on Haight last week, and the selection was great but pretty expensive. Can anyone recommend some good places to buy pretty cheap but decent used LPs either in SF, or elsewhere in the Bay Area (maybe Berkeley or Marin)?
arlipton