What does Leviticus 25:15 mean?

When you buy land from your neighbor, or sell it to them, set the price based on how many years are left until the next Jubilee. The more years left, the higher the price; the fewer years, the lower the price. Leviticus 25:15 - Modern Text Bible

(Land sales weren't permanent. The price depended on how many harvests were left before the land returned to its original family at Jubilee.)