If it's possible to take away his purchasing power, then it would be the best strategy for getting to control excessive spending of money when they are supposed to be saved. But in a situation that he doesn't have any access to any money, he will never be extravagant.You will need to learn how to control yourself and buy only the things that you actually need. You should have a budget/plan on how and what you will spend your money on and adhere strictly to it.Try and be pragmatic in your approach towards financial matters.