Surprised author didn't mention https://labgopher.com/ for finding used enterprise hardware at low cost on ebay. This hardware is cheap and typically out-of-service for enterprise, but great for home labs.
The nice thing about off-lease enterprise hardware is there is so much of it, and it's enterprise. You can easily find replacement parts, and working on that stuff is a joy, everything is easily replaceable with no tools.
My guess is that if I was used to a much faster machine, then the machine's slowness would bother me, but it in fact does not bother me. (The machine has an NVMe interface, and I have a fast SSD in there. I have the N100 CPU because I couldn't find the N200 or the i3-N305 for immediate delivery from a non-Chinese manufacturer.)
My biggest (current) problem is finding something that supports a ton of SATA drives and still is low power (though at some point even the power usage of spinning rust can become noticeable).
I live in the icy wilderness, so excess power to heat isn't a problem for most of the year.
Given how huge drives are now, 1 nvme and 1 sata/spinning rust is basically all I'd ever need (I don't do video/music/etc. )
Edit: Oh shit...just checked, it does NOT have a PCIE slot..I was sure it did :-(