Lev 25:14-16

14When you make a sale to your neighbor or buy from your neighbor, you shall not cheat one another.15When you buy from your neighbor, you shall pay only for the number of years since the jubilee; the seller shall charge you only for the remaining crop years.16If the years are more, you shall increase the price, and if the years are fewer, you shall diminish the price; for it is a certain number of harvests that are being sold to you.