Shut Down! Maybe a bit of a buff?

Let me make it very clear that I have no idea how to program games. However, I think there should be more of a benefit for shutting someone down after they've carried through a game with 30 kills. I think it could be some sort of percentage of gold is given to the last hitter (and assists, maybe?) based on how many kills the player being shut down has gotten in that kill streak.

I don't even know if a system like this is already in place, because I haven't played for too long, but I'd like to at least create some discussion. Feel free to tell me why this isn't a good idea.