Schmange buddy, I would charge this guy more than 500 bucks myself. He had no right to trash your place like that man. Not to mention he played your guitar and broke a string on it. That's getting a little too personal for my liking. I would be serving this guy a size 13 if it were my pad and then make him clean it up and pay the 500 bucks. You are a nice guy to let him off for only 500 bucks.