even if it would work, probably wont work long.
This is because ebay is starting to cash in on the buyer directly. Which means, if you buy something off ebay, you do not pay the seller, but instead ebay collects from you. once they got the money, they ask you to send the shipment, then 7 days later they pay you out. They already started that crap on new accounts, and they released a press statement that they will make this the way it works for all payments.
What this means is basically that people can cash in bitcoins, then file a claim, and watch the seller cry, because he cant prove the shipping of whatever he "sold". (if you ever had trouble with an unhonest buyer on ebay, you can have whatever you want, as long as it's not a tracking number, you will lose a dispute as a seller)
Thing is, this way of doing things leaves the seller with multiple disadvantages:
a) he wont receive his money instantly, but has to wait 7+ days for it.
b) he has the ~15 % fees for ebay and gaypal as discussed.
c) there's an even higher fraud risk than doing normal paypal purchases
Finally, both parties will have the noob problem, since I saw more than one person to date trying to checkout via tor. people just seem to be unable to understand that using paypal over tor is really bad karma.