Doesn't have to be a bit coin auction site though. Those are ebay fees and how they make their money even if they accepted BTC it would still be the same.
Would eBay or PayPal accept digital currency, it would be the end. eBay and PayPal is a "legal" criminal organisation. It's not about the fees, every one can ask as much fee as he want, but no one can open a business without an address or a company license..., except eBay and PayPal!
Try to find their contact details, business registration number or company address... You can't !