For example:
You sell CDs individually and in packs of 50. With the Bundled Item Shipping feature, you can specify that if a customer purchases 50 CDs, then the shipping would be charged according to the bundled rate – not the single rate. If a customer purchases 51 CDs, then they will receive the bundled rate for the 50 CDs with the charge for the single CD added to the bundled rate.
