This recipe will be very useful for you if you have a setup similar to the demo shop. For this example we are setting a Flat Rate for shipping a single movie DVD. When additional items are added to the cart or a singular product in the cart is not a movie DVD, the shop's default shipping module, in this example, Table Rate, will be visible while the new Flat Rate module will be hidden.
Your Checkout Shipping page will look like this with only a movie DVD in the cart:
If you add a second DVD or have a product from any other top category in the cart, your shipping calculation will use Table Rate:
This is what your Administration | Modules | Shipping area will look with the new Flat Fee module added:
