A forklift will last for only 4 more years. It costs $6,100 a year to maintain. For $16,000 you can buy a new lift that can last for 9 years and should require maintenance costs of only $3,100 a year. a-1. Calculate the equivalent cost of owning and operating if the discount rate is 6% per year? b-1. Calculate the equivalent cost of owning and operating if the discount rate is 14% per year?