There should be a limit on how many of any powerups anyone can purchase in one day. I would suggest SIX for RockStar, Likenado, Boomerang, Famplifier, Big Bang and 2X, and ONE for God Mode.
There should be a limit of 25 total powerups of any kind in a 24 hour period, and exceeding it will block purchase of power ups for 72 hours.
An alternative is to double the purchase price above six of any power ups and/or 25 total in 24 hours.
Yet one more alternative would be to impose a restriction of buying any power up that you currently own more than 2 days worth.
Have any other ideas? I want to make up something that many people can make the same suggestion to the Fubar Office, things are getting out of hand.