In George Washington's days, there were no cameras. One's image was

either sculpted or painted.  Some paintings of George Washington

showed him standing behind a desk with one arm behind his back

while others showed both legs and both arms.  Prices charged by

painters were not based on how many people were to be painted, but

by how many limbs were to be painted.  Arms and legs are 'limbs,'

therefore painting them would cost the buyer more.  Hence the

expression, 'Okay, but it'll cost you an arm and a leg.'   (Artists

know hands and arms are more difficult to pain)