Something I have learnt (provided it is true) is that aslong as you do accept returns (which, for the item in question, you did,) that means you do accept returns for change of mind. To not accept returns for change of mind, you need to put No Returns Accepted.

Perhaps a better way of handling it would be stating that you're happy to return the item, provided they pay for shipping costs back to you and don't mind being down a couple of dollars for the fee that eBay and PayPal took. After explaining all that, they'd either return it and accept it, keep it and sell it themselves or leave you the same neg as before. I'd of at least tried to work something out but yeah one more neg really won't make a difference. Most buyers, IMO, don't look at feedback.

Dave n PJ, Ooh you are awful, but I like you. (Dick Emery)

just wanted to say thanks to the OP - I've got a heap of brand new, still in the wrapping, never opened jigsaw puzzles here but I thought the postage price would deter people from buying them for even a few dollars - but you've shown me otherwise, so Cheers!