What part of the Bay Area? I get mine at Pet Club in South San Francisco, which is just west of 280 @ Westborough. They're the only decent selection west of the bay, but if you live across the bridge, go to East Bay Vivarium - awesome place. My backups are Petco, Serramonte Pets (Daly City) and Animal Connection (SF)... but they're all iffy in terms of selection, quality, and/or price. Good luck!

P.S. If you're in the South Bay, I'm not really sure where to go...