If your credit card data is stolen, you can reverse the charges and in the worst case get a new card, canceling the old one. You will be made whole very quickly. If your data is stolen, you have very little recourse. Honestly of all the things to be worried about, stolen credit card details is probably one of the least of my concerns. Besides, he's using a payment service where he doesn't even see the credit card details, so you wouldn't be sharing your credit card details, just a token for charging. And if he fraudulently charges the card, you reverse it. Your credit card details are still safe.
My personal data is worth a lot more to me than credit card details.
