How many fridges that can store 3,000 meals and are designed to be installed on an airplane do you suppose are sold each year?
Reminds me of a big scandal about plastic caps on the ends of seats on the AWACS about twenty years ago. The government was paying ~$800 for the kind of plastic caps you could buy at Lowe's for $5 for a pack of four.
But Boeing had to re-create the tooling (the government hadn't paid to retain it), assign space on the factory floor, certify the material to safety and ecology standards, train the personnel, and perform the full FAA and military certifications. For something like two dozen caps...Air Force supply procedures didn't allow them to put in a big order, so all the startup and certification costs were spread over a very small production run.
Had a similar issue myself, towards the end of my Boeing career. We had a small electronic device we needed tested on an airplane. Some of our guys were working on the P-8 Poseidon project, and aimed us at the people operating the company test bed.
There was an amazing list of things they required...certification to ~17Gs (so it didn't come apart in a crash), remote switch so the pilots could turn it on and off (it didn't HAVE a switch, it was designed to operate until the 9V battery went dead), EMI compatibility testing with everything else in the cabin, etc. Plus the fact that the functions, etc. were classified, and none of the P-8 folks had the right clearances. Our government customer wasn't willing to brief them.
So...instead we crossed the ramp to the Boeing experimental hangar. Went to the guy in charge of Boeing's fleet of T-33s.
"What would it take to carry this in a T-Bird?"
He looked at it. "Gimme a tie-wrap....."
Experimental R&D category, of course.....
Ron Wanttaja