Never deal with any Nigerian or African buyer. These are the most evil customers/buyers/ and countries in the planet earth.

If you do not refund the transaction, your paypal account will be limited in few days being involved with these types of crooks. I am 99% sure this is a fraudulent transaction.

Better , you log in to your paypal account immediately and refund the transaction in FULL if you want to save your paypal account. if your account is verified, getting second account with Verified status is almost impossible with same name and address. Paypal verify with SSN and you can not use your same SSN on second Paypal account.

I am sure, S/he is using someone elses's credit card and that will be "charged back" sooner or later.  If you are selling on Craigslist, you only want to deal with local people with CASH on hand.