Would it cost them more? yes. would it be the "number 1 priority" because it's so impactful? no, obviously not.
Maybe I'm overestimating the difficulty of making guns. But I'm aware of zero conflicts in which small arms were manufactured in situ. Even in e.g. Myanmar/Burma. The fact that even remote conflicts go through the trouble of importing arms suggests this might be more difficult than you suggest.
It's similar to services: you can your own email server, but it's much more efficient to use some vendor and let them do it for you. But if all vendors cut you off, it won't be impossible for you to host your down email, it'll just be less efficient.
Evidence against the point above that it's trivial to replace professionally manufactured small arms.
I wasn’t aware of this. Do you have a good source where I might learn more?
These are centuries-old objects. Manufacturing technology and materials science have advanced nearly 100 years since Ma Deuce first rolled off the line. Society didn't get dumber, and manufacturing has only gotten more accessible.
Just look at the current state of 3D printed firearms: they're completely useful and viable. CNC machining has never been cheaper or easier to do.
Mass synthesis of the drugs that cartels produce is trivial (that's why they produce them)
Putting drugs on trucks is trivial (that's why they do that)
Rudimentary semi-submersible vessels are impressive but you only need a few and they're not that hard to make (again, that's why they make em)
The telecom stuff they do is legitimately pretty impressive, but this too is just significant capex for long term benefit -- not so with self-made guns which are significant capex and you get out the other side a low volume of low-quality, non-dependable, often-breaking guns.