What is the ruling when a buyer and seller disagree on the value of an item purchased using non-monetary consideration (an exchange)?

Primary text

If there is a dispute regarding the value of the consideration (al-'ard) used in a purchase, the value must be determined by independent appraisers (al-muqawwimun). If bringing the item being offered for appraisal is impossible, the statement of the buyer is accepted, similar to when a dispute arises over the amount of the monetary price. Furthermore, if the buyer claims ignorance regarding the value of the consideration, the ruling follows what has been established for one who claims ignorance regarding the monetary price.