A drawing by late South African president Nelson Mandela of the door of his prison cell on Robben Island -- where he was held for 18 years -- sold on Thursday in New York for $112,575. “The Cell Door, Robben Island” -- completed in 2002 by the Nobel peace laureate -- exceeded the top end of the estimated range provided by Bonhams, which put its value at $60,000 to $90,000. The wax pastel crayon drawing shows a few bars of the cell door and a key in the lock, sketched in purple.