Kesterson Corporation has provided the following information: Direct materials Direct labor Variable manufacturing overhead Cost per Cost per Unit $ 6.40 $ 3.50 Period Fixed manufacturing overhead. Sales commissions Variable administrative expense Fixed selling and administrative expense $ 1.35 $ 18,900 $ 1.50 $ 0.80 $ 6,300 The incremental manufacturing cost that the company will incur if it increases production from 7,000 to 7,001 units is closest to: