consumer (n.)

early 15c., "one who squanders or wastes," agent noun from consume. In economics, "one who uses up goods or articles, one who destroys the exchangeable value of a commodity by using it" (opposite of producer), from 1745.

Consumer goods is attested from 1890. In U.S., consumer price index calculated since 1919, tracking "changes in the prices paid by urban consumers for a representative basket of goods and services" [Bureau of Labor Statistics]; abbreviation CPI is attested by 1971.