The phrase ‘cost an arm and a leg’ originates from the art world. In the 18th century, when people wanted to commission portraits, the cost would inflate if more limbs were included. Since detailed limbs were difficult and time-consuming to paint, artists charged a premium for them. Thus, an extravagant portrait that included an arm and a leg would, quite literally, ‘cost an arm and a leg.’ Now you know why some people in old portraits look somewhat… unarmed.
