Andy Warhol's iconic painting of Marilyn Monroe is predicted to sell for $15 million (GBP7.7 million) when it goes up for auction in New York City in May (07). The artwork, entitled LEMON MARILYN, is one of 13 portraits Warhol created for his first one-man show in 1962. An anonymous American collector, who purchased the painting for $250 (GBP128) just three months after Monroe's untimely death in August 1962, will sell the piece at auction house Christie's later this year (07).