I don't have an iphone, but don't you have to buy apps through the itunes store? couldn't you just call apple, or go to the apple store, and have them moved to a new iphone? Just buy yourself a new one and let him try to sell it empty.
I dunno. This seems to me not worth getting your undies in a twist over. If it's so damn important to him, use it to gain leverage over something you DO want.