In the U.S., sales tax is added onto the marketed price. Customers who go to a brick-and-mortar store are used to seeing a price of $99 knowing they will pay more than that for the product. In the European Union, however, Value Added Tax (VAT) is a tax on the perceived value of a product and is marketed as a component of the final price.
Conversion rates are important, but not when compared to other companies, rather against your own historical conversion rates.