I mean I think the distinction between "goods that are not wanted" and "goods that are wanted but are not affordable" is a significant one, but if you want to stick strictly to the terms of art in economics, then yes I suppose you're correct. And I didn't mean to argue his point, but rather to reinforce it. If goods, when they become cheaper, suddenly start moving again, then the goods themselves aren't really the issue.

And I mean, this is exactly 100% my experience currently. Our sedan could use replacement, it's about to hit the 200k miles mark, and given it's primarily used by my wife for inter-town transit, I would happily buy her an electric car, but a new electric car is hopelessly out of our reach financially. And I make six figures!

A car is an inelastic good that is priced beyond what the market can actually bear. This is why the used market is so insane: people make do with a secondary market because they need the good but can't afford it on the actual market. And now there's a supply crunch on that secondary market, because the primary one has risen so much.

No it is exactly the same. If people can't afford to live in mansions, then it makes no sense to build them. Nobody will buy it. It is a demand problem.