Need to count one product (a set) as 2 for shipping

Hello,
I have multiple listings for products that contain more than one item. For example there is a Set of comic books which contains 3 comic books. I sell these as a set, therefore I list them as one product. The problem is that when it comes to shipping I use Quantity to determine shipping cost... therefore when it's checking quantity to choose a shipping method it needs to look at a specified quantity of items rather than the quantity of products.

Does this make sense? Can anyone please help? I"m guessing this is out there somewhere but based on my search terms I am unable to find anything.

Thanks in advance!

Crazy I figured this would be an easy problem to solve and that I was just overlooking something small, but I'm not getting any response so it must be more difficult that I had expected.

Should I maybe try to use weight? It'd be a pain to go back and update all existing products, but if that's the only way then I guess I will.