Fraud involves a misrepresentation material to the transaction, where you rely upon the misrepresentation to your detriment. I don't see that the age of the proprietor is material to the service you would be buying or that there is a detriment - whether he's 15, 55, or 150 you're getting the exact service you're paying for, aren't you? What's the injury? Also, you claim to know his actual age so you can't claim to be relying upon his representation of being older.
If he's violating PayPal's terms of service, that's something they can investigate and act upon.

