Nothing will happen to an ebayer who does this if nobody submits a dispute.
I had a problem recently on ebay with a seller who was selling magnetic batman and robin and never delivered the figures. Then he closed his account and relisted them under another userid. Of course, I cancelled payment on paypal and credit card, and then submitted the dispute. Ebay communicated with me thoroughly about it, and though they can't disclose the private details, they now have that guy and his wife on their radar.