Using the estimated sales and production of 140,000 boxes of Chap-Off, the Accounting Department has developed the following manufacturing cost per box: Direct material $ 3.70 Direct labor 2.00 Manufacturing overhead 1.60 Total cost $ 7.30 The costs above relate to making both the lip balm and the tube that contains it. As an alternative to making the tubes for Chap-Off, Silven has approached a supplier to discuss the possibility of buying the tubes. The purchase price of the supplier's empty tubes would be $1.20 per box of 24 tubes. If Silven Industries stops making the tubes and buys them from the outside supplier, its direct labor and variable manufacturing overhead costs per box of Chap-Off would be reduced by 10% and its direct materials costs would be reduced by 20%. Required: 1. If Silven buys its tubes from the outside supplier, how much of its own Chap-Off manufacturing costs per box will it be able to avoid