This feature allows you (the site) the ability to charge a percentage of every successful auction to the seller. The amount of the final fee charged is a % of the final closing cost (winning bid) of the auction. This fee is charged for each winning bidder and based on the amount of the winning bid. Within a standard auction that fee is only charged once. For dutch auctions that fee is charged for each winning bidder and winning item. So if a total of 10 items were sold through a dutch auction the seller would be charged ten final fees based on the price paid for each of those items. If 10 items were sold through a standard auction there would still be only one final fee charged based on the winning bid because all 10 items of a standard auction are sold as one.

You can collect these fees in one of two ways:

1. Roll these final fee charges into the clients next transaction. This allows the final fees due from a seller to collect until they choose to place another transaction through the system. This means that any final fee due the site will be in the sellers cart awaiting the next time they try to place a listing, purchase a subscription, renew a listing. Anything that goes through the client side cart will contain the final fees due. The current transaction they are trying to place will not go through until they pay the full amount due which includes any final fees due as well as the cost of the current item(s) they are trying to purchase.
2. Collect those final fees at the end of the successful auction. The use of this method requires the use of the Authorize.net payment gateway. If you choose to do this method a credit card number is collected from the seller at the time of auction placement. At the time the credit card information collected it is verified through Authorize.net by charging $1 to their card. But note this amount isn't actually collected as it isn't captured. If the credit is verified that auction is placed into the system as the seller inserted it. When the auction completes successfully (either closed by buy it now bid or the final bid equals or exceeds the reserve price) the final fee is inserted into the order system to be collected when the admin user chooses to next.

Use this form to change the current price based¹⁾ increment brackets. Once you start a new bracket you must finish it with an increment that has “price field high” set to “and up”, or there will be “holes” where a price could not be charged to place a listing.

Note that if there is no "winner" for an auction when it closes, no "final fees" will be charge.

Use this field to charge based on a percentage of what the "winning bid" is.

Charge a flat fee for this increment

If you use both fields, the charges for both will be added up for the final fee total. For instance, if you have % set to 10% and fixed set to $5, the final fee charged will be "10% of final bid + $5.00".

See: Price Field Low and Price Field High