Class is not determined by wealth in every country. But certainly going by wealth in this country, there are middle class people who are rich and some who are not. The upper middle class tends to be better off. Grand bourgeois or haut bourgeois are the fancy terms for the richer end.

Americans class plumbers as middle class while they would be working class in most places. We do have working class people here who are wealthier than middle class — we determine class on social origin and the nature of their work.