Working at Mozilla should be more than money. $200k/year is more than enough to be happy in most of the world. You don't need to compete on rock stars that must live in San Francisco, and focus on people that are happy with a high paying job and have enough idealism to accept "only" $200k/year.

None of those figures are what the engineer makes, they're costs. And they're illustrative, not literal. You won't pay everyone at the same rate either for example, and not all will be engineers either, and I totally left both those facts out of it. Oh no! And also omitted the fact that a company whose vision and ideals people agree with can hire said people for less money, which again brings us back around to the point that the vision might be more important.