Let him ditch game. If he finds that he misses it and eventually comes back maybe he'll realize that he actually liked the game without being fully maxed out.

However, if you feel like being a jerk about it, here are some suggestions (not that I advocate being a jerk about it):

Let him have his rod of quickening. But give them low level encounters. He'll one shot a kobold every round. Good for him.

The other option is to give him what he wants and then give the other players more. Give Jack the quickening rod and then tell him that Steve's build needed a complete set of +5 stat tomes and a gestalt character to be happy. Since Jack was already maxed out he should be content :-P