There's some remarkable sleight of hand in "for every person working on [it]". That's a lot of people required to build a browser. Are you suggesting each of those 5000 users pays $5 multiplied by $NUM_OF_DEVELOPERS, or that you'll need [5000 multiplied by $NUM_OF_DEVELOPERS] users?
The latter. The numbers are not precise, it's just to show that you really don't need a lot of paying people and they really don't need to pay a lot each.
