Contrast that with my personal experience of items from the UK (specifically the UK, my experience is different elsewhere) where “untested” almost always means “I tested it and I know it’s broken but I want to try to get a better price anyway”. Especially when testing would involve plugging it in with the adapter it comes with and seeing that it doesn’t light up, for example.

I've had good luck from "vibe checking" the seller based on their other listings, it's usually obvious who's trying to make a profit vs who's just trying to clear out their unused personal stuff. The latter is often priced down too, for a quick sale. I'll only buy from a commercial seller if they explicitly describe the fault(s).

A whole lot of these bulk electronic sales seem to be "Here's all the stuff I couldn't fix". Either water damaged or the repair was botched. I can't imagine too many normal situations someone has 15 of the same game console they are selling in a bulk lot.