LOL, thanks for not getting insulted. I own a gym with a few members. I'll tell you that Gyms, Restaurants and hair salons are the best businesses that go out of business most often, lol.
Seriously though. It's a numbers game. Depending on the amount of space you want and your NJ location location location will immediately determine the biggest nuts you'll have to crack in terms of overhead.
In a good location rent with maintenance is about 20-25 dollars per square foot. A small gym will be about 5000 Sq ft.
So on the low end you;re looking at 5K sq ft X $20 = $100,000K
then divide the 100K by 12 months = $8,333 monthly for rent.
Utilities = 1K on average
Payroll = 2-6K
Advertising = 1k
Misc = 500.
Right away your operating costs will be about 13K on the very low end of the spectrum. Expect about 15-20K monthly overhead.
If you can get 1K members @ 40 per month you'll make 40K monthly. How do you build that to stay in business? Contracts! Be advised it's a very difficult business and most gyms go under. So don't romanticize it. Best bet is to buy an existing gym.
You wanted to do without contracts you said. Retention will be next to impossible. Seriously. I just gave you a snapshot of how it works from an insider.
Then are you ready to work there, market it, do sales, maintain it, clean it, do customer service from opening to closing? Your first 1 to 2 years will be the hardest most stressful of your life.
Be advised most business own a business as their job and lifestyle. It's a personality thing. Some just can't handle working for another person who will decide where and how much i get.It's for a different breed of individual. It really is. Make sure you're the type and know what you're getting into.