My client would like their customers to be able to mix & match colors and sizes to meet the minimum quantity and also combine items for quantity discounts. Using the example below a customer could order multiple CHEF's APRONS as 13 units RED+SMALL and 13 units BLUE+LARGE for a combined total of 26 units which would drop the price to $1.50 each. Currently they add the first batch to the cart then return to the same item and add the secondary batch to the cart where the discounted amount is only applied to that line item, the previous item is not discounted so it appears that these items are not being combined. Am I configuring this correctly? Can this be done? I studied this topic in Manual PG 171 but cannot figure how to get it to combine items for quantity discounts - PLEASE HELP!!!

CHEF'S APRON
QTY 12-24: $2.00
QTY 25-49: $1.50
QTY 50+: $1.00

COLORS: WHITE, BLACK, RED, BLUE
SIZES: SMALL, MEDIUM, LARGE

PRODUCT PAGE SETUP
Product Qty Minimum: 12
Product Qty Maximum: 100
Product Qty Units: 1
Product Qty Min/Unit Mix: YES