This paper analyzes the contributions of some of the pre-scholastic and scholastic writers on the doctrine of the “just price”. According to their perspective it is difficult to establish an objective method for discovering the “just price” of goods on the market. On the contrary, they portrayed a theory in which the only instance that ultimately determines the price of goods is the subjective evaluations of those involved in the process of buying and selling. Moreover, the “justice” of an exchange of goods or price, results directly from the absence of fraud or violence.Therefore, a price is “just” if it is voluntarily set and accepted by parties.