Earlier quoted context omitted.
That wasn't their point. In most of the world if a product's price tag says X then you pay exactly X at the register (e.g. £2 sandwich costs exactly £2 in cash, you hand then exactly £2 and leave). In the US that is not the case. Almost everything has a "hidden fee." You go buy a $2 sandwich but pay $2 + 6% ($2.12), if you get food in a restaurant you pay $price + 15-20%, an advertised $30/month cell phone plan is ac…
It's far from "a hidden fee." You simply have to know the rules. In some states, there is sales tax. In others, none. Sales tax may or may not be applied to clothing depending on state. Sales tax may or may not be applied to food, or only some kinds of food (e.g., alcohol always taxed), or only to food above a certain threshold. All in all there's nothing hidden about sales tax. It shouldn't be a surprise that people…
But that's the same thing! If people don't know or understand the rules, the fee is hidden to them. You could say that people have should educate themselves, and my reply would be that there's infinite amount of complexity that could be added to the pricing if needed: "Oh, on cloudy Wednesdays, when Jupiter shines and the Yen is down.. it's 2$ extra"