> How do you show the final price to someone when dining in and carrying out food have different tax rates?
I show two prices. Or, I show price for food and then price for packing separately. This is not a difficult problem at all.
>ow do you put the final price on an ad that will be broadcast over a large area or distributed in a newspaper that goes to same, with different tax rates in different parts of the area?
Are we now in some kind of completely different hypothetical example that is neither online shopping nor "prices in the store" we discussed before?