First of all, I don't think we should pay children to read books, they have to do it because they like it. Imagine one day this money is over, and then what? Would they read or would they stop? I think it's too risky. Moreover, one of the other questions I have to answer is about to give cash incentives to people to donate their organs, and I think we shouldn't. They do it because they want, they're playing with their lives for money and in my opinion I think it's not ethical.
But otherwise, I think the hired mercenaries should be payed to fight our wars, if it's for a good reason to fight, because they can kill, but they're also risking their lives for the rest of the people. And the others I think we sould pay are the ones who test risky new drugs. I suppose that some people don't agree with this, but because of the same reason as the mercenaries, they don't know what they're really tasting, and they're again risking their lives.
All in all, there are some things money can but, but not all of them. Some are already up for sale, and nowadays it's extremely dificult to change it.