With the things I've been interested in (and bought) pretty well on the mark for SOLD eBay auctions. Even better no price is firm and the owner will gladly make a deal on anything. (He brought this up to me himself which was a shocker!)
So far I've got Alundra complete with the map for $20, Panic for Sega CD complete for $20 as well, and Street Fighter Zero 2 Saturn import (with spinecard!) for $10. Also of note when I bought Alundra was a COMPLETE copy of Brigandine for $35 and that went fast. Didn't have enough to grab it, nor Phantasy Star 2 with the manual which was $8. (though I'm not entirely sure if that's on the low end for that game)