Leviticus 25:14-16

14And if ye sell ought unto your neighbour, or buy of your neighbour's hand, ye shall not overreach one another.

15According to the number of years since the jubilee, thou shalt buy of thy neighbour; according to the number of years of the produce, he shall sell unto thee.

16According to the greater number of the years, thou shalt increase the price thereof; and according to the fewness of years, thou shalt diminish the price of it; for it is the number of crops that he selleth unto thee.