Nothing is free. It's just that some resources are being depleted faster than others, so they become expensive, plus there are places where you can't get a propane refill within hundreds miles. Most of South America and half the Mexico is like that. Plenty of places in rural Canada where propane refill is same pain. In shore cabin you can have a huge stationary tank, in RV you can't. This problem alone is worth seeking alternative solutions - but, as I wrote already, LP stove is not the most fuel-hungry appliance.