Looks like they would rather you pay with a credit card/debit card.
BUT if you insist on using paypal to fund the transactions, that is the option you have. Looks like you have to manually send them money via paypal to that email address you mentioned and follow those directions. So next time you win an auction, they will take the money from the paypal money you have sent them.
That's very different, never seen that done before but cool to see that's an option.
-Omar