A bit more info about customs might be helpful. Here in Germany costums smarted up over the years and if they feel that the pricing is suspicious they want to see your order details, invoice and your communication. They even have put up computer terminals to be used by customers to proof their pricing claim. Over the years I have learned that it becomes almost impossible to play tricks. I bet if you undercut the official price in a worst case they will come up with the price list listed here. be careful.