I would read all the paypal stuff over to check about them, but whatever protection is provided by the credit card you use to make a purchase is there regardless of whether you walk into Macy's and buy something or purchase something online on or off eBay or wherever.
And I second the advice to be very very cautious about buying something off eBay from an eBay seller unless the eBay seller also has an established, known, and reputable off-eBay business, preferably with a brick and mortar presence.
Even though you have credit card protection, why risk the annoyance and expenditure of your time and anger cells?