Buyer doesn't pay you go through unpaid item dispute process, neither party can leave feedback, your fvf is refunded and the buyer gets a strike recorded against their account.

If they do this more than once and all sellers follow through they won't be bothering me as I have my buyer requirements set to block any member with more than one unpaid item strike.

How could the seller leaving a neg be any better than that as most of my items are BIN and even the auctions I have better things to do than waste time checking the feedback of every single bidder to see if they have what looks like a justified neg.