https://en.wikipedia.org/wiki/Composition_of_the_human_body
Iron:
Fraction of mass = 60×10^−6
~3 g in men, ~2.3 g in women.
I decided to discard elements with less than 0.1% in body.
Magneto would have serious problems to kill us with our own iron xP
Well, the idea is that you spend some of your money on increasing your income as you go along - which upgrade specifically are you talking about?