If you're in a major metropolitan I'd suggest craigslist as well. densely populated cities have more to list than small towns in east bumbleF.
E.G.Good condition one being sold in NYC for $275 minus the box/accessories. Obviously you have to look in your own area since it's not smart to make a deal for shipping since you have nothing to guarantee they will mail it. I've had nothing but good stories with using craiglist. Small suggestions if you do decide to go that route:
-Don't be afraid to negotiate price. Be realistic, but firm. Don't expect to get a $400+ phone for 200 when it's brand new and very popular (back order for some), but depending cosmetic damage/lack accessories you can get closer to it. (you can replace just about any part at cnn.cn)
-Be sure to meet in a public, well lit place (you ARE meeting a stranger)
-Be sure to power it up and test all keys as well as put in your sim card, make a call and connect BIS through the phone's email setup to make sure the PIN has been released.