Leviticus 25:14-16

14If you make a sale to your neighbor or a purchase from him, do not cheat one another.

15You are to make the purchase from your neighbor based on the number of years since the last Jubilee. He is to sell to you based on the number of remaining harvest years.

16You are to increase its price in proportion to a greater amount of years, and decrease its price in proportion to a lesser amount of years, because what he is selling to you is a number of harvests.