Makes sense!
I was also thinking there's a related rule - something worth buying used has proven itself to not be crap.
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.
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).