Your firm is purchasing a new telephone system that will last for four years. You can purchase the system for an up-front cost of $150,000, or you can lease the system from the manufacturer for $4000 paid at the end of each month. The lease price is offered for a 48-month lease with no early termination—you cannot end the lease early. Your firm can borrow at an interest rate of 6% APR with monthly compounding. Should you purchase the system outright or pay $4000 per month?