Among customers with IDs from 1 to 100, what is the highest price of products they purchased?
IDs from 1 to 100 refers to CustomerID BETWEEN 1 AND 100 ; highest price refers to MAX(Price);
SELECT T1.Price FROM Products AS T1 INNER JOIN Sales AS T2 ON T1.ProductID = T2.ProductID WHERE T2.CustomerID BETWEEN 1 AND 100 ORDER BY T1.Price DESC LIMIT 1