Cheap Heat electric add-on

Over Thanksgiving We used our Montana as an additional bedroom for relatives that were in visiting from Texas. We had the furnace set at 65f during the day and 70f at night. We also had 2 space heaters running continuously in addition to the gas furnace. 1.5 30lb tanks of lpg were consumed during this time frame. Where we live I pay right at $25 to fill a 30lb cylinder. At the rate of consumption of 1.5 tanks of propane per week it would only take 13.5 weeks to have spent $500! For me this is a no-brainer, I would rather spend $500 on the Cheap Heat system and have it paid for in 1 season than to have to run numerous small electric heaters in addition to running the gas furnace and having to worry about running out of gas! Speaking only for myself, the Cheap Heat system is what I'm going to purchase for my camper because it is more practical for MY needs. I don't want electric baseboard heaters or stand-alone electric heaters in the middle of the floor, I don't want multiple extension cords run from the rig to the power pedestal and I also want heat in the basement to keep water lines, drains and valves thawed like the factory system is intended to do. Also, if the furnace blower has to run longer with the electric add-on that's fine, the life of an electric motor is NOT shortened by running, it's shortened by the max amp draw of the start condition.