Uncle Sixth and His Fifteen Grievance-Nephews

He is an old uncle who has 15 nephews. Facing 15 lovely nephews, he always wants to give them the best things. What if the cost of raising a nephew is just too high? One nephew costs 200 yuan, and 15 of them are 3,000 yuan! Fortunately, there is system assistance, and you will be rewarded for completing the task. But why is this mission so strange? He is almost the sixth child.