Demonstration of advanced options for calculating items in the price list: some items can be marked with the "Key quantity" attribute.
Thus, for other items marked with another attribute "Use key quantity", the quantity entered by the user is multiplied by the quantity of the key item. For example, the key item is "USERS $ 50 (Min 5) *". For "VOIP $ 2 per user" and "Support $ 1 per user" items, their quantity is multiplied by the quantity of the key product "USERS $ 50 (Min 5)".