Give the full name of the customer who bought the most amount of products.
full name of the customer = FirstName, MiddleInitial, LastName; most amount of products refers to MAX(MULTIPLY(Quantity, Price));
SELECT T3.FirstName, T3.MiddleInitial, T3.LastName FROM Products AS T1 INNER JOIN Sales AS T2 ON T1.ProductID = T2.ProductID INNER JOIN Customers AS T3 ON T2.CustomerID = T3.CustomerID ORDER BY T2.Quantity * T1.Price DESC LIMIT 1