Barry's Batman Gambit to force Mark to bid $3,500 on a locker in "Enemy of My Enemy." Dave and Darrell are in on it, pretending to try and drag Barry away before he got stuck with the locker himself. It was an attempt on Barry's part to make Mark burn his cash faster, leaving something for the regulars to bid on.
Jarrod managed to trick Dave out of a locker by having Brandi bid on it. Everyone was shocked to learn that Jarrod was married and that he's married to her.
Barry's locker in "Not Your Average Bear" was described by every bidder as looking like complete junk. No one wanted it. Barry threw out a bid of $2.50 and won the locker. The locker turned out to have several antique fly traps worth $2,000, meaning Barry finished the day with an 80,000% profit on his investment.
Dave shelling out $750 for a locker with nothing but newspapers... that happen to be from the week Elvis died. Turns out they're appraised at $90,000. Dave's profit from this one locker is a few hundred dollars shy of everyone else's total from the entire season combined.