Affliction that varies based on spent FP

[JCurwen3]

Is it possible to build an Affliction that varies based on how much FP (or HP if you prefer a Costs Hit Points deal instead) you spend?

What I envision is an Affliction that can inflict an attribute penalty -x, for every y FP spent; it should be able to inflict a maximum attribute penalty -nx, where n is your current FP total (including ER if applicable).

So, a specific example, an Affliction that inflicts -2 ST on a target per 3 FP spent.

Any ideas?

[Goober4473]

I believe in Powers it suggests using the average cost for the modifier. So if you can pay 1-10 FP, you get -25% for Costs 5 FP.