Surely most people pay the sales tax, in which case you're optimising for the less common scenario. In places where including VAT/GST/BTW/whatever is normal, s

Surely most people pay the sales tax, in which case you're optimising for the less common scenario. In places where including VAT/GST/BTW/whatever is normal, shops (usually targetting resellers or contractors etc) where a significant amount of people don't have to pay the tax, I think generally both prices are listed and it's required to be very clear about what's going on.