The 10% stacks additively, each time you do the deal, this status is applied to a different 10%. If you sacrifice 10 fingers, the entire world is guaranteed basic human needs (food, water, shelter, clothing, healthcate, etc…)
Nobody knows you saved them. Would you do it?
If everyone knows about the fact that you can do this deal, would that change your mind?
Yeah, it’s definitely all ten, although I can see how I would regret that choice from time to time.
Fortunately, robot hands are pretty cool, and I’m sure that if the world were prosperous and they saw somebody with no fingers, they would all chip in to help back out. So it wouldn’t be like terrible forever, but it would definitely have its moments where it sucks.