I's say the bourgeoisie. What do you think?
They were part of the Third Estate - the First was the clergy, and the Second was the nobility. If they weren't a member of a religious institution, or didn't have a noble title, they were a member of the Third Estate. Though it was quite common for merchants and bankers to be richer than many members of the First and Second Estates, as these included poor parish priests and impoverished rural nobility respectively.