How much would you pay for a gym membership every month? Perhaps $50 or maybe $200 if you're willing to interact with a broader pool of trainers. What do you think $1,000 would achieve? Private classes with gym instructors for yoga, cardio, biking, marathons, and weight lifting? Well, now imagine what $2,500 a month gets you- not a smart bike or multiuse gym equipment, but a gym membership. Here are the three most expensive gyms in the world.