Cost of the UN

I heard today that the US pays about 25% of the total cost to run the United Nations…about $1.8 billion. Not to mention what it costs to protect the delegates of the UN while they are in New York at the UN headquarters. I find that to be a bit excessive. I would think that all nations should pay equally if we all are going to get an equal say. Seems like we are paying money to get other countries to disagree with us.