Dell Wyse 5070 off ebay. 2TB nvme in an external case I had laying around (just so happened to have been shuffling hardware around on other computers). Gave it to a relative who has their own setup with a battery backup and stuff. Tailscale and Duplicacy. 1.5 years and only issue I bumped into was the first external case I bought was cheap and bad. Went with something slightly more reputable and it's been rock solid since.