Write SQL query to solve given problem: Please list all the vendors' usual selling prices of the product Hex Nut 5.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T1.StandardPrice FROM ProductVendor AS T1 INNER JOIN Product AS T2 ON T1.ProductID = T2.ProductID WHERE T2.Name = 'Hex Nut 5' GROUP BY T1.StandardPrice ORDER BY COUNT(T1.StandardPrice) DESC LIMIT 1