I love REI's return policy. Last month we bought an Easton seatpost there for about $100. It worked out fine for me, but the next week we found the exact same Easton seatpost on sale at Nashbar for $40. That was too much of a savings to pass up, so I was going to return the REI one, but since it had been installed they wouldn't have been able to resell it. So I put the identical but brand-new Nashbar one in the REI box and returned that.

Was that cheating? Maybe it was. I would have returned the used one, otherwise, and this seemed less wasteful overall. (They always ask you if the item has been used or damaged, to determine if it can be resold, but that is generally the only question asked.)