If you've been to a mystery dinner theater, it's the same general principle, a group of people get together to solve a mystery. One is escaping a room, the other is questioning actors to solve a crime. It's just the escape rooms get rid of the actors and dinner parts and focus more on props.

As for low cost, I meant to start one. Service-based, low amount of employees, not much need for location if you focus on appointments, etc.