Greetings & Welcome!
I’ma huge fan of low tech, simple, cheap, reliable, and relatively fool proof. I don’t go cheap because I can’t afford it, I go cheap because more expensive isn’t necessary, and it usually means more complicated and less reliable.
I don’t use propane or solar myself. My fuel of choice is kerosene, diesel, or cooking oil, whichever is cheapest or handiest when I need it. My stove and heater will run on any of those. My next air conditioner (swamp cooler) will run on fuel instead of electrical power as well, using a stirling engine to power it.
For electrical, I want cheap but reliable too. My primary system is an isolator connected to my ~$20 used deep cycle battery from a junkyard. I usually get 5-7 years out of those batteries. The total cost of my primary system is under $100 all in, and that includes the battery box and 8 accessory outlets. I also run a similar deep cycle battery for my starter battery, and each battery will last about a week without driving. I have low battery cutoffs on each battery to prevent over discharging, but even after they cut out, I still have plenty of power to start my van. The end result is I can boondock without driving for about 2 weeks.
My backup plan is a $99 generator combined with a $29 battery charger, that will also work on shore power if available. All my normal equipment/accessories are 12v, but if I need shore power for anything, the generator can provide it, anytime, & anywhere.
I’ve been really happy with my choices, not because of the cheap price tag, but because of the comfort, convenience, and reliability, the things which are important to me. Good quality doesn’t require a high price, or the latest & greatest whatever. Nomads have been successfully living as nomads for thousands of years, long before electricity or automobiles. History can be a great teacher, maybe better than many of the more modern methods. While I certainly enjoy a few electrical luxuries, I try not to rely too heavily upon them.
"Always avoid complicated solutions to solve simple problems." ~ OffGrid