I always assume the bottom 10% in any market is going to be garbage, whether it's shoes, jeans, food or anything else. Of course knowing that doesn't help if you are really destitute.
Lots of people make the same assumption, and companies take advantage of that. E.g. if they want you to buy a bottle of wine at $10 a bottle, they'll place plenty of $10 bottles on the shelves, as well as some $7 bottles, with the assumption that you'll regard them as bottom of the barrel crap.
