Angels are happier than men and devils, because they are not always prying after good and evil in one another, and eating the tree of knowledge for Satan's gratification.
What is the price of experience? Do men buy it for a song? Or wisdom for a dance in the street? No, it is bought with the price of all the man hath, his house, his wife, his children.
The reason Milton wrote in fetters when he wrote of Angels and God, and at liberty when of Devils and Hell, is because he was a true poet and of the Devil's party without knowing it.