What do you mean by expensive? It’s free open source software no?

I’m pretty sure he means 12$/year. 6$ per month is pretty expensive for a domain.

That doesn’t match my experience with AUR at all. Usually it pulls a specific git revision and checks the hash. This also ensures that the build shouldn’t suddenly fail to some extent.

Though it’s entirely possible that it’s not like this for all packages, though I find it kind of counterintuitive since your package manager wouldn’t know when to perform an update in this case.

A diagram of the relevant Hypervisor/VMs/containers + Network information would be helpful.

From where and how are you testing DNS? Did you use dig and specified the nameserver directly?