It appears the refrigeration topic is one of "energy". The 12-volt DC compressor units are power thirsty. The 120 V AC units require an inverter, 12V to 120V and are thusly power thirsty. The absorption LP types are lacking somewhat in effective cooling resources but are not power thirsty.
So, one has 3 choices, choose one and prepare for the means to support its energy needs. Somewhere in one of my Physics classes we discussed thermal dynamics. The laws of physics have not changed.
If one uses the 12V DC compressor units or one of the 120-volt AC systems with an inverter, then one best plan for lots of battery capacity, 200 to 300 Ah useable, and likewise means to recharge same. Generators and solar of adequate capacity and utilization are necessary.
As to what the company supplied, I'm sure not only the supply vs. demand influenced the costs, but likely the bean counters had their input as well.
Bottom line, it is a series of compromises. Investigate and research first and then choose one.
Bob