What pushes the wealthy to want to become wealthier is determination to stay on top, they understand that wealth can vanish if it's not sustainable. I believe that wealthy people have phobia for poverty, they are afraid to become poor like the those that comes to them for help. This is the reason why most financially wealthy people will do almost anything to become more wealthy because it is better to go from grace to grace than descending from grace to grass. Everybody wants the good life and those that have it knows that if they relax they might not be able to compete with other wealthy people.