How Much Can I Charge You to Work a Lot?

If I own Lot A, you can't step on Lot A unless I let you. Why would anybody pay me money to do anything on a field with nothing on it? If nobody owns Lot B, you can go there and harvest 100 utils worth of food. Your other option is to go work Lot C and you can get 10 util's worth of wealth out of that. So the most I could possibly charge you to work either Lot A or B is 90 utils because then you would work it, you would get 100 utils' worth of stuff. But importantly, maybe two people that want to work Lot C are not homo economic cases where they will walk 30 miles