User Story:
The client sells 100+ shoes or socks at a time with varying designs and sizes. Their goal is to:
  1. Show these differences in quantity across size and design on the final purchase order to manufacturing.
  2. Take into account the entire SKU( type of shoe ) ignoring size or design to calculate volume discounts by SKU.
Ideally, this could be done via a Calculated Roll Up based on the SKU