Assembly plants in Jefferson City and Omaha supply warehouses in Des Moines, Kansas City, and St$.$ Louis. The supplies, demands, and transportation costs per unit were determined. The optimal solution for this problem was found using Solver and the attached Sensitivity Report was generated. If the supply at Jefferson City could be increased by $6$ units, what would be the change in the total cost of the optimal solution?

Round your answer to whole dollars and include a sign if required