Hello,
You have to accept the return if the seller opens a dispute. You just need to be safe and cover your bases. Inform the buyer that you will accept the return, as long as it is returned in the same condition that it was received in. Tell them to ship the item with insurance and signature confirmation. When you receive the package, make sure to make the postmaster wait while you open the package and confirm that it is indeed your bag in the box. Either way, ebay says to accept the package but get the postmasters information (so it is a third party that watched you open the package and saw what was in it--like an elmo bag or box of rocks) so it helps with your claim. If you refuse the package, it goes back to the buyer and paypal will still refund them and you have no grounds to get your bag or money back. This is what I have heard. Good luck!