Krauss Company purchased a construction crane three years ago for $180,000. The crane has a current book value of $100,000 and operating expenses excluding depreciation of $12,000 per year. The current market value of this crane is $85,000. If the old crane is kept five more years, its salvage value would be $10,000. A new crane would cost $70,000, have a useful life of five years, and would require $13,000 per year in operating expenses excluding depreciation. The new crane has a salvage value of $20,000 after five years. Based on this information, Krauss should