Have your looked into owning a franchise of the bigger ones like Planet Fitness, 24 hour fitness, anytime fitness? Then potentially open up large scale ones like LA. Tbh the only private owned gyms that are successful are ones that focus around crossfit. You'll need space and equipment for that and for any gym you'll need a decent amount of qualified trainers. In a group of 200 only 50 know what they're doing. The 150 either want to join a program or in there for the environment.
I personally don't like the idea of starting your own private one as the risk is way too high. (Say planet fitness opens up 10 miles down the road).
The local gyms I know of are very expensive and for really competitive people they are worth it but an average Joe would rather drive 10 miles to a cheaper gym.
Really depends on what you want to do with it. Not all gyms are the same. If your business model is fair, equipment is good, great hours of operation, and a you can micromanage well then people will come.
This post was edited by WolfBody on Feb 8 2016 10:07am