Good Job!I think you did the right thing.
I have 3 boys and that's how it works here. You break something of someone else's you are expected to replace or make compensation for it.
My only question is why would you give the money back to the child who broke it? I don't believe that would be postive re-enforcement(my opinion only). If anybody, would get it back (in my mind) it would be the child who's toy was broken who should be the recipient (not the one who broke it) so they could put it towards another.