Norwegian and Dutch family travelling to Stavanger (Norway) via Guangzhou and Amsterdam.

Hi,
It was just brought to my notice from Pullmann hotel at Guangzhou Airport, that my family will need a transit visa because we are spending 6 hours at the Pullmann hotel at Guangzhou Airport. I am considering to cancel the hotel if the transit visas are expensive. Our family consists of two adults, a 10 year old, a 7 year old and a 3 year old. How much will we be charged for the 5 persons if we decide to stay at the hotel? Kind regards.