What is the ruling on a sale involving a concession (Mahabah) made by a sick person to a non-heir when the preemption claimant is also a non-heir?

Primary text

If the concession made by the sick person to a non-heir buyer does not exceed one-third of the value, the sale is valid. The non-heir preemption claimant may claim the property based on that price because the price established the sale, and the discounted nature of the item does not prevent preemption. If the concession exceeds one-third, the ruling follows the same principle as a Mahabah made to an heir.