In order to reverse a F&F PayPal transaction that you actually initiated, my understanding is you will need to lie (possibly under oath) to PayPal, which I dont recommend doing.
Hopefully this isnt a lot of money for you and you can use this as a way to teach yourself how to better defend against scammers.
$50 doesn`t matter, I want to protect forum users from ANY FUTURE SCAMS with other users where it might involve more serious amounts.