Only way I can see this being profitable is if it's done on a gym-style subscription basis. You pay $X/mo for access to the service. Your X buys you Y x 2hr sl

Only way I can see this being profitable is if it's done on a gym-style subscription basis. You pay $X/mo for access to the service. Your X buys you Y x 2hr slots which you have to book in advance to manage availability. You can have different tiers for X and Y, but you would need to make sure you have good availability, otherwise people would cancel their subscription if they can never find a good slot.