EBTH does not allow sellers to bid on their own items.  (Sellers can face legal issues in doing so.)  Seller accounts and email addresses are blocked from bidding on items listed by that account.

As a seller, you represent and warrant that you will not engage in shill bidding. Shill bidding happens when anyone (including family, agents, friends, employees, or online acquaintances) bids on an item with the intent to artificially increase its price or desirability, usually on behalf of the seller. You will be held liable for and agree to indemnify EBTH against any damages incurred by EBTH due to your related shill bidding.