I would probably also include the wealth one owns and not just money (because thats useless, they would just use a different currency) and set it to like 40-50 houses in value. If they own a company that gets bigger the country gets shares

50 Houses might seem a lot in value (especially depending on what kind of building) but it already would distribute a lot of wealth + allowing the dream of being filthy rich with less consequences to the rest of the population

Because its just an idea i dont think about the specifics of the exact limit and such