Another way to look for non crap, is to check the used value of something. E.g. check swappa. If people are still paying a lot for an item after it is used, usually a good sign. If they are not and you still want it, get it used and save a ton.

Another good way, check how much insurance costs. e.g. How much is that extended warranty going to cost on one car vs another. How much is home owners insurance in one neighborhood vs another. Insurance companies that make mistakes here go out of business.

Price is not a very good indicator of quality

Especially for older 'thing' you might be looking for. If it is at all collectable, the price will be higher, regardless of quality.

Ice cream makers are one thing I have found that for. White Mountain made a really high quality product, but the used market is obscene, because people collect them apparently (at least in my part of the country).

People still try to sell their used crap. So how do you define if something is worth buying used ? For some people everything is worth buying used, even crap

That's also seen as survival bias!