You can demand a return before refunding. If the buyer chose Not As Described for the reason, you will have to send return shipping.
If the buyer is in the US, this can be done through Shippo*. It may be possible for other countries too.
If the buyer used a freight forwarder, you only have to send return postage for the address of the freight forwarder.
If the buyer does not return the item, you do not have to refund.
If the buyer Disputes through Paypal, bonus! PP demands that the buyer always pays return postage.
The tricky one is buyers who claim through their credit card company, but those problems are very few, and come under Cookie Jar Insurance.
While you can Block payments from overseas PP accounts you'll have to go to PP to do it. I never have because overseas buyers make up more than 10% of my customers. I have more problems (number and percentage) with US buyers.
The only problem in my opinion with freight forwarders is the 4.4% charge, a 1.5% premium. OTOH you got a sale and kept 85% of the payment. Think about it, which is better $8,50 on a $10 payment or $0.00 on no payment?
Actually, I'd put the 1.5% premium for overseas PP payments under Cookie Jar Insurance too.
EBay has its own freight forwarding program, for US and UK sellers. It's called the Global Shipping Program and sellers choose to be in it, opening their sales to non-US sales while providing Delivery Confirmation, cheap domestic shipping rates, blocks on disputes over duty and taxes, etc.
* Oops! Didn't notice I was on dotCOM. This is a new option for Canadian sellers like me who could not until recently provide any return shipping labels to non-Canadian customers. The information may apply to US sellers, but you'd have to investigate it yourself.
