Well I guess I just don’t have the same connections you do. A cheap 100ah battery will run you $500. Buy a name brand and it will be more like $800+. Solar panels run $1/watt +/- . An mppt controller $100. An inverter $150-$200. Now add a whole bunch of copper wire, fuses, circuit breakers, mounting brackets for the panels. You are at $1500 before any labor. Oh did I forget the cost of the new Fridge? I think my payback will be way out there....also you can run a standard fridge on 400 watts panel and 100 amp hour lifepo... so under $500. so maybe 1.5 years to pay back....
Seriously though. I camp 2-3 months a year in the camper. Often in wooded areas in the northeast US so panels only help so much. I am putting in 600w of panels, 600ah of 12v lifepo4 batteries, and a 3000w inverter. My goal is to last a week plus (about the max I can go without dealing with dumping water) wihtout wanting to worry about power or a generator. Will not run the AC’s will not use fireplace or electric heaters but will run the fridge and hot water tank on propane. Use the microwave, coffee maker, etc....