Summary
His second opinion is: contracts say that lawful it is to obtain a thing that costs more than the thing’s price. When a buyer decides he needs some things he looks for a better price that is lower, but not higher. And a seller needs to sell things at a just price. The price of things is their just price. If one person cheats other person, it means they injure these persons. The author thinks that in contracts one way dealing is accepted, not double dealing.
Another point of the author is that buying and selling can be advantage too. An advantage ...