i think the problem with this is that it removes the idea of progression, and actually makes having low Wi much better. if it's going to for eg, cost 10% to get an aramor, theres no sense of it becoming an easier process as you get stronger.
but let's also say that some creatures use more Wi than you have currently. there are two options: 1 make it a % over 100, so for eg, 150%. or cap it at 100%
the first option would mean that having LOW wi would be more beneficial, because you need to gain less to reacgh 150% , 10,000 > 15,000 means only needing 5k instead of 100,000 > 150,000 needing 50000. this would mean as you get "stronger" and should have an easier time in the world, you actually have a *harder* time
if we go with the second option, that would mean that theres no sense of progression and working towards those goals, there would be no reason to fight or train to reach the things beyond you, because everything is attainable with the default amount