The single biggest problem I see with crap like Modular Terminals is...
Aside from Marco Qwent, they're completely worthless, as this sort of garbage was written out of Engineering a while ago, so these things serve no other purpose. Then add to that that these are a manufactured product, which means somewhere someone has to be making these. And since no one would make something for free, it means someone's selling them - just not to us, and that's just stupid.
There are very few things that one cannot buy, though some are easier to come by than others. Need some replacement MRI machine magnets? https://www.dextermag.com/products/magnetic-assemblies/mri-nmr/
How about some platinum electrodes for your home hydrogen production operation? http://www.ravindraheraeus.com/products/pelectrodes.htm
Not things anyone would generally think of buying, I'll admit, but that's sort of the point here - if someone makes it, someone sells it. But clearly that's not the case in Elite.
There are so many items out there that have no other source than scavenging, murdering or receiving as a mission award.
Well, you have to remember how far in the past this game is, these things just aren't as readily available yet.