A pink cocktail dress worn by Audrey Hepburn in the movie Breakfast at Tiffany's sold for $192,000 at a Christie's auction yesterday. The auction house said that had expected the dress - worn in the scene where Holly Golightly discovers her brother has died - would sell for somewhere in the neighborhood of $30,000. Yesterday's sale of film and entertainment memorabilia also included Marilyn Monroe's script for Something's Got to Give and a program from the JFK birthday party at Madison Square Garden that featured Monroe singing.