Cash cash or cash.
I am in the credit card transaction business. I would strongly suggest not taking credit cards. There are many reasons looking from both sides of transaction. Main reason for provider is charge backs, if you do be sure to get signature, make a copy of card on manual swipe and check card name with drivers license. This will maybe guarantee of no charge back. Another reason is there is an electronic proof he was at your place of business buying something.
From the hobbyist side everything listed above.
PM me if you have other questions.