(05/29/08) ATLANTIC CITY - A New York gambling company is buying Atlantic City's Trump Marina Hotel Casino for $316 million, and will rename it "Margaritaville," the companies said Thursday. Coastal Marina LLC, an affiliate of Coastal Development LLC, is buying the casino from Trump Entertainment Resorts. Trump Entertainment is the casino company founded by real estate magnate Donald Trump. After the sale, the company will have two remaining casinos in Atlantic City: The Trump Taj Mahal Casino Resort, and Trump Plaza Hotel and Casino.