quote from Blizzard's Associate Level Designer, Andy Kirton.
Auction System
The auction system was one feature that definitely intrigued me. Instead of simply yelling that you have an item for sale, or posting it into a channel, you'll actually be able to put it at an auction house; at least that's the current design idea. "When you put your item up, the easiest way to think about it would be Ebay," Andy told me. You'll see your item up for auction and can either specify a price or let people bid. Once someone pays the set amount for an item, the money is taken from their account and put in either your account or sent to you via the mail system. To pick up the item you've won, you'll head to the nearest Inn and check your mailbox outside. I asked if there would be any type of "you've got mail" notification and was told probably not; as it is something they want players to check at least once a day…when you stop by an Inn, check your mail.