I like the idea of a gradual powerdown + instant powerdown tax

10 week power down = Free
9 week power down = .5% tax
8 week power down = 1% tax
7 week power down = 1.5% tax
6 week week power down = 2%
instant = 5%

Why punish your own powerup with 5% tax and get rewarded by everyone elses powerups?
I don't like this concept because it would lead to poeple making "ponzi scheme" comparisons.