Header level Scales for purchasing

We have labels that we purchase and our vendor has offered scaled pricing if we combine different materials within the same size. As an example, I have 4 labels that are all 1" x 4" and my scales are 10,000, 50,000 and 100,000.

How can I create a header level condition that will combine these 4 different materials to obtain the best pricing? I've tried condition groups and also tried isolating these 4 materials into a contract, but I still can't find a way to combine this at the header level.

Thanks in advance for the help

David Lewis