just pay cash
credit card charge 20% interest, you wanna pay that on 800 dollars? haha..
That means even if you pay off the next month you owe extra 13 dollars. take 6 months to pay off and its extra 80 dollars, a year and it's 160 dollars... And that's assuming you are disciplined enough not to purchase anything else on the card in the meantime!
Always if there's a choice of credit over cash, take cash!