Price-tags are compulsory in Iceland. If store owner doesn't display prices on the products in the window or, on the shelves, he can be fined. And if there is difference in prices between the window display and inside the store the customer has the right to demand the lower price. Here in The Netherlands about 70-80% of the products are marked with price and more than once I've seen the same product with 2 different prices in the same store. In Iceland the store has to display prices for whole kilos or liters and each item on the price ticket. This is to make sure that the customer can easily compare prices. In The Netherlands I've seen one product showing the price for 100 grams and another comparable product showing the price for 1 kilo.