Cahill Lumber manufactures mulch and wood bark from a joint processing operation using wood as the raw material. For a recent month, 8,000 pounds of mulch were produced having a sales value after split-off point of $21,000. 4,000 pounds of wood bark were produced having a sales value after split-off of $14,000. Using the net- realizable-value method, the portion of the total joint product costs allocated to mulch was $12,000. The amount of joint costs allocated to wood bark using the net-realizable-value method would be