"Group" tickets: The price of the tickets increases as more tickets are sold. So, it may happen that there is only one ticket left with the lowest price (e.g. 30Euro), and the others cost more (e.g. 40Euro). If you buy two tickets together, you will be paying the highest price multiplied by the number of persons (in our example 40*2=80Euro, instead of 30+40=70Euro). Always check that the price for the group is not higher than the initial price per person multiplied by the number of people in your group.
