Yes, moot point now. And not that a DJI warranty is anything of value anyway, but in my opinion, you would be making an already dodgy situation worse. I just looked at that price and thought wow! Wish I hadn't missed out on that! But then when I looked at the numbers (and as it turns out, I guess the P3 battery is actually $150, so saving even less) at the end of the day I would have said no thanks. And this from a guy who buys non working P2's on eBay!
I do wish the buyer many hours of happy flying with his P3. If I buy anything new, it will probably be a solo. By the time I would ever pull the trigger on a P3, the P4 will probably already be out!