We will encounter many problems like how to play Rodri's Merchant in the game. Many users will have a headache when encountering this problem. After reading the solution to this problem written by the editor of Source Code.com, you will find that this problem is really simple.
This running business is similar to reselling information , taking advantage of the information asymmetry and commodity prices in big cities.
Just like the salt on the left is cheaper, the salt on the right is more expensive.
Then we can buy salt in the city on the left and sell it in the city on the right.
The difference in price is our profit, so we need a horse and information.