I didn’t miss it, but didn’t loop back. Apologies.

I disregarded that as a solution in my response to that, because it’s not really a solution to OP’s request. Yes, they are cheaper. No, they are not functional for this need due to lack of PCIe. Running SSDs on these devices is not a feature because of the bus speed and connection limitations.

Sure it’s possible. No, it’s not functional for the needs requested here, or even a good suggestion. If somebody wanted a RELIABLE backup target using SSDs, this is the last possible scenario I would even suggest, and only if working from a box of scraps.

I’m not discounting your point that it’s cheaper at all, but it’s like…okay…if someone asked me where to get steak, because they need steak for a recipe they are cooking for dinner, my response shouldn’t be “Well, you could get steak right there, but it costs $X, and you can get Chicken wayyyyyyyy over there. It’s not beef, and it’s not what your recipe calls for, but it’s cheaper and possible to get.”

You’re asserting a position into justification for an argument that doesn’t exist. OP isn’t asking what they could theoretically run backups to. That could be an esp32 board for even cheaper. It’s also an even worse solution than an RPi. It’s just not what they’re asking for.