I would just like to clarify. I was in no way referring to any specific auction software when I said it would be easy. It is probable that the juice is not even included in the formula to the end of the auction. It would need to be introduced earlier. Assuming it is a static, straight percentage, for every item and every bidder, that would not be difficult to add, either as part of the total or as an additional field, making the bidder do the math.
Of course as it always is, it would have been easier to include it from the beginning. Any retro-fit custom piece always comes with added fun. The secret is to bill for more fun than you run into....
