During my usual bargain surfing I found at American Airguns' Classified section:
a Benjamin Discovery, .22, (no pump) $190
an RWS 350 Magnum, .177, fired only 5 times, w/ 3-9 x 40 scope +2 piece mount, muzzlebrake, $385
another RWS 350 Magnum Scope Combo, never even cocked, no caliber listed, $399
a B40 in .22 with less than 50 pellets through it, I think the scope comes with it, $220
RWS Diana mod. 48, .177, with a rather nasty scratch on the stock, $239
Walther Falcon Hunter, .22, less than 10 shots fired, owner getting rid of it due to elbow problem, $180
a Theoben "Crow Magnum" (Eliminator), .22, shipped in hard case, $825 [I'm not so sure this is a good price, I only suspect it is. Don't take my word for it I'm not that familiar with Theoben guns]
..you get the idea. The American Airguns Classifieds (
http://www.airguns.net/classifieds/classifieds.php ) can have some decent deals, though you'll also see some people asking way too much, so be careful there. Give 'em a good looking through every once in awhile.
In my experience the best bets for finding decent deals are The American Airguns Classifieds, the Classifieds here at GTA, and Airguns of Arizona's Used Guns Section.