carriage trade

The term carriage trade originally referred to business
transacted with rich clients, but with time, it has also come to
describe the group of rich clients themselves.

As a general term for the well-to do, carriage trade doesn’t
necessarily carry the connotation of ‘fashionable,’ but it does
imply a certain degree of polite behavior.

Nouveaux-riches rock stars and ill-mannered sports celebrities
need not apply.

carriage trade = well-mannered rich people