There's a difference between a good deal because of store error, and a good deal from your own lying.
Like..when we went to Sears Hardware to buy one of those 3 piece tool chests..they only charged us for one. I was prepared to pay for all 3, but I'm not gonna argue with 66% discount, idiot workers, I'll tell ya what.
Though not checking the price was silly of the cashier, usually Best Buy people always double and triple check.