Most auctioneers typically get 20% of the sale price. Now, there are a couple of ways to do it. They can take 20% off what they give you, or they can take 10% and then charge the buyer the other 10% (called a "buyer's premium"). Some places charge a smaller percentage if the sale price of an item is over a certain amount (such as 10% of the sale price of a car that sells for $6,000). Many auctioneers also charge extra if you have an item with a reserve price (meaning you set a minumum price at which you will sell, and "reserve" the right to decline a sale if the high bid is below that price). This is to pay them for going through the motions of selling an item that does not sell.