I live in about the worst area in the country - NYC is probably the most expensive market (SF is probably a close second). Lots of crap bikes end up here, and most of them are sold for way more than they're worth.

Hit up the yard sales, church auctions/sales, and flea markets. Salvation Army is worth a look. Even if the bike is a pile, they've usually got usable parts on them. Post in the ISO/WTB thread here too.