(a) Greater amount obtainable under other circumstances; no preclusion of commercial reasonableness. The fact that a greater amount could have been obtained by a collection, enforcement, disposition or acceptance at a different time or in a different method from that selected by the secured party is not of itself sufficient to preclude the secured party from establishing that the collection, enforcement, disposition or acceptance was made in a commercially reasonable manner.
(b) Dispositions that are commercially reasonable. A disposition of collateral is made in a commercially reasonable manner if the disposition is made:
(1) In the usual manner on any recognized market;