It is not realistic to envision a society in which the wealthy do not have disproportionate control over policy. Except for periods when governance belonged to the prophets, and the era of the Khulafah Rashideen; such a scenario has never really existed in history.
No theoretical models that have been imagined to limit the power of the rich actually work in reality.
The best that we can do is to recognize this inevitable dynamic, and struggle, within the framework of the real existing power structure, to attain our rights. The only way to do that, is to inflict consequences on power by disrupting their interests.
Fortunately, the interests of the rich are both transparent and vulnerable.