I would seriously advise you pay for the item. If not at least communicate the problem - Perhaps send them a note "lack of funds, can't pay." Or just simply "decided no longer want this." At least inform them if your going to be a non payer if that is your decision. Your post fails to mention the dollar value involved and an idea of what the item is which is a key detail. Your an ebay seller, what is wrong with just paying for the item and honoring your bid (sounds like you got it cheap), listing it in your store or auction? Or is this due to lack of money? I too sell on ebay and expect payment within 3 days of auction close. I let ebay handle any non payers which are fairly rare, hopefully they get an unpaid item strike and of course I add them to the block list. When I was allowed to neg them for non payment, this was automatic on my part. The auction house will likely relist the coin in the next auction. They most likely will block you from future auctions or who knows they may be relieved they did not give it away lol. I suggest you keep a journal to handle the ongoing details of your business / investment. At least honor your bids unless your just broke - you can blow them out or retail them later on the bay if you do not want the item.
OP, if this was a GreatCollections auction, please phone me at 1-800-442-6467 or e-mail ian@greatcollections.com. Regards, - Ian