it makes some effect for bitcoin prices or not if 1 of the big pool closed?
No. Mining is affected directly by the price of bitcoin. The price of bitcoin is not directly affected by mining.
I always thought the price of bitcoin wass like any other product that is on the market, supply and demand... since so many new coins are introduced into the market each day there has to be someone out there willing to buy those coins at a given value, if they are not being sold the price drops if people are wanting more than what is out there the price rises (or atleast that is the way i assumed it worked)