Earlier quoted context omitted.
What's the point of even having a price sticker if what's charged is more than what it says? Are some people exempt from the sales tax added? Is it dynamic depdending on the total amount charged?
Tax-free sticker price is good for making you aware how much you are paying for the product and how much goes to the tax man.
In the UK we have a default all included price on items for example in supermarkets, but in wholesale shops targeting businesses prices will be shown as with and without VAT as businesses can reclaim it. Makes perfect sense, reduces cognitive load, makes comparison of prices easier, means the consumer doesn't need to understand the implications of the tax system on every purchase.