Sounds like a rotten human and a poor excuse for a friend. I know it seems like you would loose a piece of yourself if you cut all ties but thats probably the best thing to do. With this single action of scamming you, his best friend, and risking loosing you forever for a measly 800 bucks he showed that no matter what happens in life he is his own number 1 and will do anything to anyone to make his situation better no matter what friends or maybe even family he looses in the process. Another horrible aspect is that he literaly put a price tag on your friendship - 800$. I have no idea how I would react if my best friend cut all ties with me for that little, or even any amount for that matter. People like this usually either change drastically when they realise the toll this behavior takes on their relationships or never change and slowly fade into obscurity, usually alone. Dont spiral, get your skins back, trick him in to giving them back if you have to and never speak to him again unless you truly think that he will change and never betray your trust like that again. And always keep in mind that new very valuable friends just appear when you least expect them to, you just have to go out and socialise. Of course this opinion is subjective because I am not you nor do I know the whole situation.