You just paid $450 as a lesson to learn what the word "friend" means.
I get at least 8 credit card offers each week in the mail, and can get money from a number of legitimate sources. Around here, there are payday loan places and pawn shops on every block. The guy has plenty of alternatives.
A payment plan would have been a piece of cake. Even though he is broke right now, I'll bet he has money each week to buy cigarettes, beer, fast food, pay for a cell phone, and other stuff like that. He could easily pay you $25-50 a week.
Write the money off as a lesson learned, and find some new friends.