To top it off, this auction was falsely advertised.
0.5 BTC was advertised as having a "retail value" of 5$.
Keep in mind that you don't need to pay anything to play, you can just as easily post items for free and earn credits to bid on other items. It's a bartering site first, and penny auction site second because that added twist makes the auctions fun. But you don't need to give me a dime to use any feature on the site.
Regarding the "retail value" it's sort of hard to put a real value on progressive auctions because the payout could be .5 or 4.5 bitcoins. But they way the site is designed you have to put a number there.