Leviticus 25:15-16

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.