Be careful with such deals. Credit cards are charged on monthly subscription. Even though OP's service will be a one time payment, there is no guarantee he wouldn't generate a huge bill for the next billing cycle which may result in card getting charged the next month.Also the card details will be saved on the profile which I suppose can also be easy to unauthorised access.
I wouldn't recommend anyone doing this just for a couple of bucks.
Not to mention, the OP could be under aged. There is evidence to suggest that. Even a pre-paid CC could lead to trouble if that's the case.