@audricd @salarua I second this. If you're starting, an unused computer (laptop, desktop, raspberry pi or other single board computer, whatever) you already have is perfect. Or an old computer a friend gives you, or eventually a cheap second hand computer.
You can do A LOT with very little computing resources

Agreed! Don't spend at first. Reuse an old computer. See if you like doing this!

For the most part, yes. Some things, like SIEMs, IDPSs, machine learning (GPT, Stable Diffusion, etc.), and other such processing-heavy things should be taken into consideration and "fed" properly.

I don’t recommend hosting your own email server, as it’s very labor-intensive to keep your emails out of people’s spam folders.

i'm not going to use this email server for real-name business, and i'll likely only be emailing people who contact me first. that said...good point

May I ask, why not an rPi? Is it because of the unreasonable prices?

ideological differences, i guess. i used to trust them right up until they hired that surveillance professional and shut down everyone who told them that that was a bad idea