Magento Open Source, 1.9.x

Quantity Increments

Unlike a unit price, the quantity price refers to multiple items of the same product that are packaged together and sold as a single unit. A six-pack of soft drinks is an example of product that is sold in quantity increments.

How to set up quantity increments:

1. On the Admin menu, select Catalog > Manage Products.
2. In the list, click to select the product you want to sell as a package.
3. In the Product Information panel on the left, select Inventory. Then, do the following:
a. Set Qty for Item’s Status to Become Out of Stock to the lowest inventory threshold for this item. (If necessary, clear the Use Config Settings checkbox.)

The number should be a multiple of the number of items in the package. For example, for a six-pack, the threshold might be 6, 12, 18, and so on.

b. Set Enable Qty Increments to “Yes.”
c. Set Qty Increments to the number of units included in the package. For example, 6.
4. When complete, click the Save Config button.