With CStore Essentials you can add modifiers, these are usually items that are sold in Singles or multiple quantity at different price points but with the same barcode. A good example of this is breaking you Case of beers and selling them as Singles.
Go to Pricebook -> Item. Click on the Modifier button on the far right corner. Then Click on “+” or add new to add items.
2. Enter the Scan Code (Include all the digits, the leading small number and trailing small number at the end) , Assign the Scan Code Modifier and Retail Price (ex. 6 for Six Pack of Beer) and Click Add Item.