I think it's fair to say the answer is "a lot". Especially in cases of fraud, there's not going to be any money in the merchant's PayPal account to debit. They

I think it's fair to say the answer is "a lot". Especially in cases of fraud, there's not going to be any money in the merchant's PayPal account to debit. They were gone long before the chargeback came through, and they aren't going to leave a legitimate bank or credit card linked to the account to go after either. PayPal takes those losses.