Yeah, it's right on their auction site under the
link "Mandarake Auction 2002". Link is above.
The paragraph says:
"On the day of the auction, the winner of an item
will be determined by the one who placed the
highest bid amount. In addition, to offset the
high cost of running a huge auction, Mandarake
will charge a 10% commission fee on top of the
winning bid of each item. So after the highest
bidder is declared, the winning bidder will need
to pay the following... Bid price + 10% of bid
price as commission fee + shipping fee (price
varies depending on the weight)"