Ebay absolutely lacks the seller protection to ever make this kind of transaction. If I purposely tried to design a market that supported this kind of fraud, (even encouraged it, in a nurturing "please do this" sort of way). I couldn't do better.
"We have reviewed your PayPal account and found that you are operating as an e-currency dealer/exchanger including the sale of electronic media of exchange (such as electronic money or digital currency). Per our current Acceptable Use Policy for Money Service Businesses, PayPal may not be used to operate a currency exchange, bureau de change or check cashing business including the sale of Bit coin."
So PayPal knows what BTC is, they just straight up ban digital currency sales.
Paypal doesn't work that way, mate.
If the seller required a good account history, and stuck to the US, he may have not had these problems. Arguably those buyers could have screwed him on anything (remember the story about the rare violin destroyed at Paypal's request.)
There are things worth a lot more than $90 bought and sold on eBay every day. I would argue that buyer to seller reputation and thus integrity is more important than the reputation of the marketplace or medium of exchange.
It must work out better for eBay that way. But it sucks to sell anything of high value.
But, eBay probably made the decision by simply asking who it is better to frustrate: sellers who have very little choice of viable venues at which to sell, or buyers who have a plethora of choices from which to buy.