I think this is ignoring the feedback loop between market demand and product design. It is entirely possible for cheap products to crowd out good ones such that good ones no longer exist in the market no matter how “informed” you are. Indeed, as discussed in this very comments section, appliances are already there, pretty much every brand of fridge or washer/dryer is shit now regardless of how much you spend.

It is entirely possible that the overall social optimum is that the very cheapest tier of product needs to not exist in order to get the volume for decent models to have good economies of scale etc.