Import Tax is a tax set forth by the Country administration that decrease the earning cutting out the tax from the price of items at the marketplace when citizen selling the item doesn't have a citizenship of the country. Tax revenue is added to the country's account.
Example: If a citizen with Spanish citizenship decides to sell one unit of Food at the marketplace in France for $1.00, and France's import tax for food is 50%, and France's VAT is 5%, then the earning for the seller will be only $0.45 (1.00 - 55%). So the import tax is now a real loss for the seller, and not anymore just an obstacle for the price competitivity. This new way of taxation makes the export activity almost always less profitable than placing offers on the local market.