That's a great deal on engine block heater! I felt putting one in earlier rather than later was a good plan. The hole for it could get plugged up with gunk over time. Installing one years later may become more difficult. That's my logic for doing it sooner (when my Mirage was relatively new yet) at least!
I forgot about the guys upgrading to lightweight alloy rims & 185/55r15 LRR tires, too! Those guys can blame Top Fuel for coughing some money for that, too!