Cost an Arm and a Leg

A popular story claims that 18th and 19th-century portrait painters charged customers extra for each limb included in a painting, so a full-length portrait with both arms and both legs visible "cost an arm and a leg" more than a cheaper head-and-shoulders version. Painters certainly did charge more for larger, more elaborate portraits, but there's no actual evidence they billed by individual limb. The phrase itself is a much more recent American coinage, first appearing in print around 1949, roughly a century after the portrait-pricing custom it's supposedly describing had already fallen out of fashion. It likely grew out of two older, separate expressions: "I'd give my right arm" (a 17th-century way of saying something would cost you dearly) and later wartime slang about the devastating cost, in the most literal sense, of losing limbs in combat.