I bought the strip when I purchased my Polar Cub in 2004. It cost $50 at time of purchase of the A/C, and it was my understanding it was $150 to add later. Since I installed it, I have used it one or two times. It is borderline useless, and would be exceptionally disappointed had I paid $150 for it. As it is, I just wasted $50. I have a Walmart portable heater ($30) that does a better job. It is much quieter, smoother/quieter air flow. In using the Polar Cub heat strip, I have found it to be very noisey, and the windchill from the fan uncomfortable.
If you purchase the strip at $50 I suggest you give it a try. To add later for $150, I think you are wasting your money.
Wayne