Prices under the contract may not be changed unless the travel package contract explicitly states this and specifies exactly how the price change is calculated. A change is justified only in the case of changes in transport costs, relevant exchange rates or taxation, for example. However, the price may not be increased in the 20 days preceding the agreed departure date.
If the tour operator finds that, before the start of the journey, it must significantly change the price, it must announce this as soon as possible. In this situation, you can cancel from the contract without cost or accept the change.