I listed an item on eBay.co.uk as collection or uk delivery only. The winning bidder then told me he’s in another country but he would organise a courier to collect at his expense. I wasn't particularly happy but I did agreed to this. Now he has the item he claims it is broken and wants a refund. Who would have to pay any return postage? Ebays policies say the seller might have to pay but as far as I can see they don't specify when - in this case the buyer effectively chose the buyer collects option and presumably it would be his responsibility to return the item?
You're right, the buyer would pay return postage. But it's up to you whether you accept the return at all. Items collected by a third party on behalf of the buyer are not covered by ebay buyer protection.
