From what I read earlier about ProPay, they are an accepted method of transaction on Ebay.
This is from the ProPay site...
ProPay also offers flexible solutions for home owners associations, property management companies, lending institutions and auction sites such as eBay.
They may say so, but according to eBay, they are not. And even if they were, most sellers only accept PayPal.
http://pages.ebay.com/help/policies/accepted-payments-policy.html