I've just gone down the hardware route and bought myself a refurbished Dell Optiplex with i5 6500 and 16g ram for under £70 on eBay.
So far it's running Home Assistant, Docker (I have a bunch of stuff in Docker rn and most of it doesn't work but hey, I'm learning), OMV and an ARR stack with Plex that takes up half the 500gb drive on it. Currently awaiting a powered SATA to USB cable so I can see if I can mount some of these old HDDs I have lying around.
Anyway point being it wasn't expensive and seems to be running Plex fine.
I have my Arr stack running on a Windows VM. I'd like to run it in Docker but I'm finding the VPN to be troublesome.
I was told in here that 7th gen chips are good for hardware transcoding. This is the 2nd number of the chip set. So my Optiplex has a 6th gen i5 in it (i5-6xxx) and it's doing the job.