Leviticus 25:14-17

And if you sell anything to your neighbor or buy from your neighbor’s hand, you shall not oppress one another. According to the number of years after the Jubilee you shall buy from your neighbor, and according to the number of years of crops he shall sell to you. According to the multitude of years you shall increase its price, and according to the fewer number of years you shall diminish its price; for he sells to you according to the number of the years of the crops. Therefore you shall not oppress one another, but you shall fear your God; for I am the LORD your God.