Did anyone of you have experience of using a virtual currency to do something similar?
Same goes for the whole "value of money" shtick too, honestly. Your son is playing Xbox because his life hours have been spared (by your hand!!!) from the virtueless misfortune of closing Pizza Hut every weekday at 11pm. Don't teach him the value of money, teach him the value of time. Buy him books about the director of his favorite game and support the passions and interests he latches onto when he finds them. If you try to launder all of your fears through the Xbox then you're no better off than where you started.