If a buyer fails to pay, they most DEFINITELY MUST GET A NEGATIVE! The negative feedback should be automatic! It should also annul any opportunity for a buyer to leave negative feedback for a seller when they have not paid. This is a pure and simple equation that eBay will not absorb. Their dysfunctional policy helps to hide the scammers and allow them to do it again and again and again. Negative feedback is also a good indication of the type of buyer you are dealing with. It's pathetically no good at all if all you see is positives when these willful non-payers cause a lot of trauma along their merry way. And eBay are happy to keep such measures in place. You can fight against this bad situation by documenting non-paying cases where eBay has REFUSED to post a negative rating against their name and then send it off to the ACCC and ASIC as this constitutes harbouring scammers and will only lead to other sellers being defrauded.