Technically speaking, your not spending anything. And if there are problems that arise, make sure you have AppleCare. Plus if you wait too long, you posted yourself that you weren't sure if he would (later on) buy it for you. Get it while the going's good.
True, true. But knowing him he's also capable of calling me an impatient idiot for not waiting a few extra weeks or saying "Why the hell did I spend so much money for THAT laptop then?!" if the GPU fails.