If time is money, it seems moral to save time, above all one's own, and such parsimony is excused by consideration for others. One is straight-forward.
"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.