to $14.00. Sales of C decliae by 200 units, while sales of B increase by 300 units. Relevant Costs and Differential Analysis Cornerstone Bank paid $120,000 for a check-sorting machine in January 2013. The machine had an estimated life of 10 years and annual operating costs of $110,000, excluding depreciation. Although management is pleased with the machine, recent technological advances have made it obsolete. Consequently, as of January 2017 , the machine has a book value of $72,000, a remaining operating life of 6 years. rage valinitiof 90