If you want something small and cheap, it might be worth getting a used thin client PC.
I got a cheap £20 Igel thin client from eBay as raspberry pi’s were still far too expensive, plus I already had a spare 4GB ddr3 sodimm to drop into it and a 120gb wd green ssd that I’d stripped from its case and fitted internally into the thin client.
After upgrading it one ended up with a 1.2ghz AMD GX-412 cpu, 4gb DDR3, 120gb sata ssd and an external usb 3 1tb hard drive i also had laying around.
As a component of my homelab, it’s running Debian 12, docker with a few containers (pigallery 2, Libreddit, portainer, searXNG), it’s my backup Emby server and my main Pihole and PiVPN client.
Completely silent, sips power and still has capacity spare to run more containers and other projects that catch my interest.