Blizzard announced today that Diablo III will allow players to buy and sell items from each other using real money via a virtual marketplace within the game. Each currency region will have its own auction house, accessible in-game. Players will have to pay a flat listing fee per item, and set initial bids and buyout prices just like they would on a real auction site.. Buyers can set their bids to automatically increase up to predetermined amounts rather than paying the buyout price as well. When the item sells, Blizzard takes a small percentage of the sale.
Any item can be sold in the auction and players have the power to sell it for whatever price they want. Blizzard claims that it has no plans to sell items directly to customers. The auction will be for players by players.