I've bought motorcycles on charge cards--people do it all the time, since finance rates on motorcycle purchases are stupid high (like 16%). The general problem is that most cards have single purchase limits (typically $5k in my experience), so you'll initially get rejected and have to run it through twice or more to get the full amount, IF they allow it at all. Expect a call from your credit card security department. As mentioned, they always make you pay the extra 2.5% that they get charged for the transaction on the card. I'm too lazy to do the calculations, but I'd guess it'd be cheaper and easier to just buy the darn miles, heh.