I got an i5 tower almost 10 years ago from

https://ithacareuse.org/

for use as a home server, it has a ZFS RAID 1 where I replaced the drives once and I guess I should again soon if I care about the warrantee. I did have a challenging upgrade because Ubuntu made a /boot partition that was too small to reliably update the kernel but I had a spare SSD sitting around which let me just install the OS on the new SSD and swap it in without any risk. It runs the ubiquiti controller, plex, and a few other services. It is not a powerful server by any means but it is massively overpowered for what it does which is better than being underpowered. I messed around with appliances in the 2000s and they inevitably left a bad taste in my mouth. They had 10% of the power of a real computer but cost 70% as much or they used an i3 and you couldn’t install a GPU —- penny wise and pound foolish.