Like others, I’ve had good experiences with eBay- just look for reputable sellers (good reviews, not a brand new seller, etc). Most of what I bought was fine, but the ones that were dead on arrival I was able to get replaced within their warranty window. Just be sure to test what you get as soon as it arrives.

I found UrBackup to be very easy to use. Very little nitty-gritty setup and configuration required to get started. I have a feeling those with more experience will (rightly) pick apart if I’m missing something egregiously bad about it, but it worked for my small homelab use cases.

It also works in the “other” direction- if you’re already using compose files, you can point dockge to their existing location (stacks directory) and it will scan and pick them up!