Exhibit 10-2 presents an incremental analysis of the two alternatives. All rel-evant costs are listed. Because the machinery has already been purchased and neither the machinery nor the required factory space has any other use, the depre-ciation costs and other fixed overhead costs are the same for both alternatives; therefore, they are not relevant to the decision. The cost of making the needed cartons is $28,800. The cost of buying 20,000 cartons at the increased purchase price will be $30,000. Since the company would save $1,200 by making the cartons, management will decide to make the cartons.