This isn't just a money/toy issue - this is an anger issue in an 8 year old. That needs to be addressed, if not already and he needs to be taught how to handle his anger. We all have anger, even as adults but children who never learn how to handle it are the adults who grow up to do much worse things than break a toy. I would try to get to the root of what made him angry to begin with to want to break a toy of his brothers.
I wouldn't give him the money back either. Doesn't work like that in real life and honestly at 8 years old I think they understand a lot more than what adults want to think they understand.