currently you have to pay before entering the Gym so my idea is add ticket gates to any business for example if you want control fees or check people with receipts on exit
so for example i add Gym and add entry gates and set up subscription and one off tickets so once NPC buys from clerk or ticket machine then he or she enters the gates and uses the equipment
Another example if NPC has setup Gym in very small shop with no space for gates so add subcription/one off fee choice box when player enters so they can chose how long subscription lasts etc
so length could be based on Weekly or Monthly Or yearly
so same method could used for Nightclubs and future business
check out gates - a speical gates to check valid receipts on exit - this useful if you have self checkouts in supermarkets or any other stores but also fast food restaurants with food ordering kiosks
this would reduce crime as well
Ticket gates - same as checkout gates but used for entry or exit or both to check tickets if paid or not also checks staff tickets to allow staff entry or exit