I use old Mac Minis that were cycled out from a company and replaced. An e-waste laptop is still probably cheaper, but you can still find the older model Mac Minis fairly cheap too. I have 2 of them that sit vertically side-by-side in a small rack with my router stationed above them. They both run Elementary OS.
Here too. Free 2012 Mac Mini that's been servering away for a couple of years already 24/7 on UPS power. Gets a deserved smile every time I look at it :)
I'm looking at replacing my 2018 desktop machine (a Thinkcentre Tiny) soon with one of the new AMD 395 mini-pcs. When that happens, the Mac Mini will be retired...
I think mine are around the same year. Such great machines for random shit. I tried to run an AI cluster across them and it kinda struggled 😂. It was a fun experiment.