I just encourage you to read their Terms of Service.
The problem is a multiple dimension issue.
For one, the TOS insists that you have a tracking number from a recognized postal service to prove that the package was shipped to the correct address, and received.
The credit card company requires the same. If the seller can not prove to the CC company that the item was shipped and received, then the seller gets no protection from the credit card company.
That is specifically why PayPal's terms of service required a delivered item to have a postal tracking number. Because if the credit card company comes back on PayPal, PP will lose the case without a tracking number.
Ive documented some of the transactions that I have made with Bitcoin via Ebay/Paypal. I also have documented a list of scammers to be aware of.
http://xbttrades.wordpress.com/