Price is a necessary but not sufficient requirement for quality, but that's no reason to throw out the idea. Harbor Freight is also not a bottom-barrel brand these days.

Cars are actually a great example. $30k will set you up with a Camry hybrid for >20 years. If you can only afford to finance a $15k econobox, you'll end up paying extra on interest, maintenance, and fuel while your car spends more time in the shop.

IMO this theory gets unfairly maligned by a strawman of "price == quality".