That's exactly how I would like to do it but wasn't sure if that's allowed. My son has learned so much from doing it and he knows he has to pay for things he wants outside of the normal. It took a while as at first, he would spend all the money the second I gave it to him, but now he actually learned to save what he earns as he knows things like new video games, rocks (he collects rocks), etc comes up that we make him use his own money for. A few times missing out and now he actually saves and when he wants something larger he knows he just has to work and make the money for it.
I figure