Years ago, I had a buddy open a private gym.
He's a firefighter and wanted extra income. So, he bought a repair shop right next to a Popeye's Chicken. He renovated the repair shop and had limited memberships to 60 so all bills associated with the space would be covered. But to his surprise, he ultimately got 110 members in a year.
Everyone was issued a digital number to enter the facility so personnel weren't need and you could workout at any time of day.
He was successful and had the gym for almost 8 years.