MGM Grand, the host hotel-casino for the megaboxing match between Floyd Mayweather Jr. and Manny Pacquaio on May 2, expects a 35 percent revenue windfall from the fight weekend compared to the room, food and beverage revenues on a typical weekend. Some 98 percent of the hotel’s 6,800 rooms are booked, with room rates, as of Friday, starting at $1,600 a night for May 1 and 2.