Antares
macrumors 68000
Donate it to a charity and use it as a tax write-off.
He's 15...probably doesn't pay taxes yet. 🙂 But I second..or is is it third/fourth the idea of donating it. Erase the HD and install Pather, fresh. Many people could get good use out of it.
Or, you could gut it for parts and sell them. Keep the case and do the fish tank conversion mentioned above.