[Jedd]

The relatively exotic Cortex ARM, along with reliability, challenges with USB & microSD, and (at least here in AU) cost & availability challenges for the 'larger' boards, really put me off heading too eagerly down the Pi path.

A few weeks ago I picked up an ex-enterprise server with 256GB ECC RAM, 24/48 Xeon cores, and a handful of disks - for AUD$1000 (~ 600 USD)

Yes, it's a noisy box, and yes 2.5" SAS disks are expensive & small - so you want storage separately - but the same applies to a RPi or NUC based lab.

It draws about 100W while idle (and in a home lab environment it takes some effort to make it sweat)

Proxmox installed and runs like a dream.

I'm sticking with Nomad over k8s (or variants) for container orchestrator across several Debian VM's in the one box -- so I'm effectively relying on ECC, dual-PSUs, and hardware RAID5 for my ersatz HA.