Before the 10th of July and after 10th of August:

One week: Nok 125,- per night
Two weeks: Nok 100,- per night
Three weeks: Nok 85,- per night
Four weeks: Nok 75,- per night
 

In the high season:

One week: 10% discount on the day prices
Two weeks: 20% discount on the day prices
Three weeks:  30% discount on the day prices
Four weeks:  35% discount on the day prices