Honestly I think money is rarely if ever a motivator. Most scientists and mathematicians I have read stories about seems to be driven primarily by curiosity, desire for recognition and the challenge of beating a hard problem.

Even many rich people are not motivated by money per say. Many who do well in business are really doing business much the same way as if we play a monoply game. Their desire is really more about "winning" the game. Money is just a sort of measurement of how well they played the "game." They may not care that much about the material wealth itself.

Sure everybody wants a nice car, house, good food and stuff like that. But one does not necessarily need to get that rich to have all those things.

Antropologists have studied this phenomena quite well. Interesting economists are quite clueless about this. Many of their models go wrong because they assume money is the prime motivator, when in reality humans crave status. Money can be a way of showing status, but status can come in many forms. For a scientists status is not necessarily money but could be having your name on an important paper, nobel prize, your own lab or something simiilar.

For many in business, status may be more derived from having many people who report to you. There has been examples of cases from business where efficiency experts found out that there was no need for many of the people who reported to the top managers. Yet that kind of efficiency advice rarely got implemented despite potential to save money. Why? Because the feeling of importance, power and status derives in large part from having people who boss around. A top manager would likely prefer a lower salary but with people to boss around than a high salary but with nobody reporting to them.

Measures of status will of course be highly cultural. Hence in some societies the rich will indulge in very expensive habbits while in others it may be less noticable. Thorstein Veblen and David Graeber both have a lot of interesting things to say about this stuff.