A buyer's premium is a percentage of the sales total that is retained by the auction house. For example, if you win an item that costs $1, the total charged will be $1.15. This goes to cover things like advertising, credit card processing fees, site hosting and other administrative costs. Most auctions with Bird's Nest will have a 15% premium. This fee is made front and center prior to bidding to ensure buyers are aware to factor that cost into their bidding. You can get some amazing deals at auction, or hard-to-find collector items that make the fee worthwhile.