Then don't print the price on at manufacture time. In any case, why is it any more reasonable to presume or mandate that the price be the same everywhere befor

Then don't print the price on at manufacture time. In any case, why is it any more reasonable to presume or mandate that the price be the same everywhere before tax and different after tax, than it would be to presume or mandate that the price before tax be adjusted to be the same after tax? Surely sales tax is not the only cost that varies between sales channels.