I've looked at these auctions, but the closing prices are always ridiculous ... glad I didn't bid now
I've heard that UA will sometimes buy items off of Ebay to find out who was selling them ... and you can guess the rest
When you look at the prices that are being bid for these items, it's obvious that less experience persons that your average Flyertalker are bidding on them, so they may not even be aware they are breaking SkyMiles rules ...