One of the advantages of buying direct from Disney is the ability to use a credit card. We used our Mastercard when purchasing our first contract direct from Disney. The ability to use the credit card was very handy since we made our initial purchase on the Magic cruise ship. The resale company we have used since the initial purchase does not use credit cards.
We use the Disney Visa for almost everything we do in Disney. including buying points. You can make out really well on the credits, just be sure to pay it off or you lose any benefit gained by using it.