Dan's RAM 1500, which was purchased for $15,000 three years ago, is now broken. He can either repair it for $4,000 and continue using it for the next two years ($4,000 value at that point) or purchase a new F350 for $16,000. The F350 will be worth an estimated $5,000 in two years and decrease operating expenses from the current $400 monthly to $300 monthly. What should Dan do? Show your calculations and discuss all relevant factors.