Not too long ago I made the (very stupid) mistake of putting a stack of platinum sheets on the AH when I thought I was putting a single sheet. I had manually turned the stack in 11 pieces and 1 piece so that I could sell them separately. But I didn't notice when auto-sort put it back into a stack.
As a result they got bought for 100k (150-200k less than they are worth.) I got in touch with the buyer, Filipo, and asked if we could trade back or make an arrangement for the mistake. He was nice enough to send me an additional 160k since he never intended to buy a stack for more than that. Decent players still exist! Thank you for your honor, not many in this game have it left.