Fable 2 - Cannot pry it out of my sons hands...

Now I need to decide if buying him a copy is worthwhile.

He has quite a few friends playing it right now, and the online co-op is actually fun for him.
But, I have been leery of him playing due to the fact that he goes through games like water.
And if he hits a snag, he gives up too easy.

Usually he waits to buy games with his allowance until they reach the 30 or 40 dollar mark (we have taught him frugal shopping quite well).

But, he has REALLY played for almost as many hours as I have.

Yet, he played another game of mine, Viking, up to Campaign 2 (3 Campaigns total), and has stopped.
I asked him if he wanted to play that game while I played Fable 2, and he decided to watch TV instead.
But, while he was playing, he always kept saying it was awesome (and it is...I SOOO love that game. I am on the final parts of Campaign 3...WooT)

But, I think this gives you an idea of how good a game Fable 2 is (especially for a young boy who LOVES FPS games on a regular basis...) if he wants to keep playing it...

The wife is still working on finishing Culdecept.
Yet, she stated that she wanted to watch me play Fable 2 tonight.
The reason for this is last night I played a little as she carved pumpkins for work.
She would look up once in a while and make suggestions or ask questions...

This is always a sign of interest on her part, as she is hard to please (for example, she wanted to put AoC on the back burner for now to finish the Culdecept game first)..

So this goes back to the original statement...do I buy my son his own copy, and have him work off the allowance?
I really want to teach him NOT to impulse shop is the real gist.

What would YOU do?