I found a very good Giant MTB for my wife with Deore 8-spd for $45 on craigslist. Comes down to knowing your bike specs and value.

Around here, there's tonnes of "vintage" and fixed-gear crap going for ridiculous prices because there's people with money who don't mind blowing it. There's no way a low-strength 1020 steel frame that weighs 8-lbs and have been converted to single-speed with chrome-plated steel seatpost, chrome-plated steel 27" wheels and rusty chrome-plated handlebars should be going for $350. But hey, it's a "fixie" and you too can play wannabe bike-messenger with one...

And a scammer was trying to sell a Nishiki "used by Greg Lemond in the TDF" for $1350... hmmm... that price sounds familiar...