Those things are fixed at purchase though aren't they? I don't pay a lower sales tax in a different state because I live somewhere else, and I don't pay less sales tax on a book if I buy it in the same transaction as something with a different levy. Europe has VAT on most items, but the rates are different based on what you're buying, where you're buying it and where you reside, but we manage it

The POS system knows how to calculate the cost of each item, why can't they just out that on the sticker instead,.