Not a parent but the xbox seems to be too big a part of the equation.
I guess it is a great idea if you adequately connect the loss of the xbox to his actions but it seems that would take a lot of reinforcement of that message.
The "shit i cant play all these games" and thoughts like that would be taking up so much space when the "why" he can't play them is the most important.
Again. Not a parent so I dont pretend to know WTF I am talking about here.