Er, back on topic, I see where Inertia is coming from. The idea of a deposit or transfer fee makes sense for real world online auctions. The auction house has to make money based on usage of the site, not necessarily the specific transaction amount.

IMO, it should work like this for Kyoubai:

To list a transaction, you have to pay a deposit fee (calculated based on minimum bid & reserve OR buyout, not both)

If the item does not sell, Kyoubai keeps this deposit fee as compensation. Failed auctions are harmful to Kyoubai’s reputation, so this encourages Sellers to list auctions with reasonable buyouts and reserves.

If the item does sell, then Kyoubai refunds the deposit (minus 0.1% of the item’s final selling price as a transaction fee)

In other words, Kyoubai should be seeing a cut of all transactions, good or bad, as a fee for use of the service.