How much per unit of Konbu does Mayumi's charge?
Mayumi's is the name of the company; how much per unit of Konbu refers to UnitPrice where ProductName = 'Konbu';
SELECT T1.UnitPrice FROM Products AS T1 INNER JOIN Suppliers AS T2 ON T1.SupplierID = T2.SupplierID WHERE T2.CompanyName LIKE 'Mayumi%' AND T1.ProductName = 'Konbu'