[Phantom]

Here's my thinking on this. Your friend did crack your bumber, now fixing it will leave it being not the same as b4. He is your friend and did tell you, but he still damaged it. I'd go with find out how much a replacement of the same kind would cost get him to cut a check for that, and then either get the replacment or go after market. That imo is not asking to much, nor trying to gouge your friend.