Who is the customer who purchased the largest total cost of products in a single order?
largest total cost refers to MAX(SUTRACT(MULTIPLY(DIVIDE(Sales, SUTRACT(1, discount)), Quantity), Profit))
SELECT T2.`Customer Name` FROM east_superstore AS T1 INNER JOIN people AS T2 ON T1.`Customer ID` = T2.`Customer ID` GROUP BY T1.`Order ID`, T2.`Customer Name` ORDER BY SUM((T1.Sales / (1 - T1.Discount)) * T1.Quantity - T1.Profit) DESC LIMIT 1