DigitalDilemma

How we’ve done it recently:

1. Put domain on cloudflare or another registrar that supports an API. Generate a token with the right privs.
2. Use certbot with the cloudflare plugin, and that token, and generate whatever certs you need within that domain using the DNS01 method.

No need to have port 80 open to the world, no need for a reverse proxy, no need for NAT rules to point it to the right machine, no need to even have DNS set up for the hostname. All of that BS is removed.

The token proves your authentication and LetsEncrypt will generate the certs.

It’s fine, but not going to be the cheapest.

Cheap to buy: Any old PC desktop, really. Most will run linux and windows fine, depending on what you want. Anywhere from free to £100. If you have an old desktop or laptop already, use that to start with.

Cheap to run: Any mini PC. I run a Lenovo ThinkCentre M53 for low power duties. Cost £40 and runs silently at 10watts, idle. (I have a secondary, much beefier server for other stuff that runs at around 100w which lives in the garage)

But plenty of people do run mac minis as home servers, often on Linux. They’re fine - just do your homework on the CPU ability, how much ram you can add, and whether you’re okay with external disks if you can’t fit enough inside.