Frequently, traders overbuy or change their minds on pins they have purchased and return them to Disney (Pin Traders, etc.). These returned pins are put away and brought out for resale every Friday morning.
Disney's pin return policy is as follows: If you have your original receipt of purchase, you can get a full refund or credit on your credit card. If you do not have the original receipt, you will only be able to exchange the pins for other pins or merchandise in the store. Pins must be on their original cards/packaging with price tag in tact.
I heard there is a new addendum to purchasing returned pins just put into place a DTP. Customers will only be able to purchase up to 5 LE pins at a time. Making it a bit more fair to others hoping for a pin find.
Hope this helps...Disneyboy