Is $100m too low or too high?

Too high. A small handful of CEOs have started making >100M in annual comp recently[1], but outside of the very highest paid CEOs, even top executives don't make that kind of money. (Although they certainly might see a capital gain in excess of that amount on their stock and options when the share price goes up.)

[1] https://www.bloomberg.com/graphics/2021-highest-paid-ceos/

Yeah, I assumed that was TC (in which case for a CEO the majority of that will be shares not the base salary) - but of course most CEOs don't run Apple/Google/Microsoft/Amazon/etc.