To cover the price question, we're clarifying to:
Because the tax rates may be variable based on the buyer's location, it's difficult to include in the price. In the US, listing prices without tax is completely standard practice as well. So this is probably the most reasonable compromise.
Any price listed for your resource must accurately reflect the price paid without taking any other steps (such as enrolling in a subscription service). If your price is listed exclusive of tax that may be applied, please indicate this in the description.