What is the ruling on going to chalets and parks that have a high price for the purpose of recreation and entertaining the family, and is that considered extravagance?

There is no harm in entertaining oneself and one's family by going to parks that are free from objectionable things. As for the high entrance fee and its relation to extravagance, it varies according to people's circumstances. What is considered extravagance for some may not be so for others. Extravagance is exceeding the limit, and people differ in that regard.