I do the same, but with Dell 7060s.
There are thousands of them coming off lease for sale here in Australia.
8500T or 8700T chips are fantastic. They can officially run Windows 11 and have have hardware transcoding built In, so are great for a Plex server!
I’ve upgraded one of mine with 2x 2GB SSD and 64GB RAM.
Never any issues and it runs 247.