Sorry to hear about this. I hope someone catches up to this guy one day.
Something I've seen in the distant past was for a thief to hijack someone else's account then rob as many as possible before disappearing. Ebay may shut down that account, but the thief says "so what", and moves on. I don't know if this is still a problem on ebay, but just one of the many reasons I quit using them years ago.
One thing I always used for larger transactions was cash-on-delivery. Buyer and seller are both then covered by the shipping agent. One gets the item when they pay the shipper, and the other gets paid. If the other party didn't agree to COD then I would avoid the deal.
Plaz