I'm thinking it may not necessarily be a scam targetted at you, that you're just an unwilling participant and stand to get caught in the cross fire. I noticed today that eBay.com have a money back guarantee, maybe this is a scamster trying to access this and the 2 separate ID's (maybe more if they have done it to others) might fly under the eBay radar.

I'm thinking this would definitely be something to alert eBay Trust and Safety to AND PayPal.

Maybe we're wrong and it is all legit, in that case, no harm done, investigations will reveal this.

Plus, if it's on your record, it just might help if there are unjust claims made against you in the future. If eBay/PayPal want to refund them, that's their business and let them do it out of their money, not yours.

Just protect yourself, I think the US rules will apply to your here, so you may have to send by a method that proves proof of lodgement, tracking AND delivery to protect yourself.

but keep eBay/PayPal in the loop and follow their advice.

Best of luck with it.