Thats a way high price, but the concept is solid for the right application. In my old popup, I installed 2 computer case fans in the top section behind the fridge along with a baffle to help direct the air. They pulled air over the cooling coils and moved the hot air out of that space. This had 2 effects on the camper. First, the fridge got alot cooler and ended up using less propane, as it cooled much more efficiently. Second, the counter top above the fridge no longer got warm and stopped melting my daughter's chocolate bars for smores.
I wouldnt be able to give a percentage of efficiency with the setup, as I took no baseline measurements before the fans were installed, but Ill tell you that the first weekend after I installed them, it was 85+ degrees and I only turned the fridge up to level 8 (out of 10) and it froze a dozen eggs, yolks and all.
I still have to look at the configuration of the fridge in my TT, but if it will allow for it, Ill be installing them in that too.