As someone who is really tried of going through the small pain to pull a new cert every 3 months and then apply it to multiple machines.. what's the norm place for just buying a 1 or 2 year certificate? and is it pretty cheap?
You should use a reverse proxy server so you only have the cert on one machine.
I actually made one for myself in go that's been pretty fun. You can try it if you want (https://github.com/fsmv/daemon) but you should be able to set it up with apache or nginx as well.
It really comes down to automation... I've mostly used Caddy as a host and reverse-proxy for personal stuff, as well as in a couple workplace projects, the support for named domains is well baked in, and there are extensions for plugging into various dns providers if you want broader wildcard options.