Collecting gold coins after all prizes - is it worth it?

Adding more elixir, allows you to upgrade Homer, Marge, Lisa, and Bart. According to EA, the upgrades will be highlighted somewhere in the game, after this event is over. I will go for gold coins to get more elixir, until hell freezes over, it's the end of humanity, or the event ends. Which ever comes first, and, i'm betting on this event ending first.