Yes it is a real problem I too as a seller have every week non payers, or some cancellation or another. Yes Ebay does gives them a strike, but unfortunately thats good i suppose if they keep doing it they can get banned from the site, but with not being able to leave feedback for the non payer it dosen't warn other sellers. You used to be able to leave feedback for buyer and seller, its a shame as the buyer can now do as they like.