Everyone needs a certain amount of money. Beyond that, we pursue money because we know how to obtain it. We don't necessarily know how to obtain happiness.
"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.