They’re at it again. Back in January we reported that MGM resort fees has been raised by quite a bit across all of their properties in Las Vegas. That increase saw the daily fee at their most expensive resorts rise to $50 per night, but apparently they were not done. Now, less than a year removed from the last rate increase, the resort fees have gone up again. This time, they’ve hit $55 per night at their flagship properties in Sin City. While MGM resort fees at Bellagio, Aria, Vdara, and The Cosmopolitan, have increased to $55 per night, other…