I have created a promo code say 'FREESHIP'
Subtotal equals or greater than $50
Apply the rule only to cart items matching the following conditions (leave blank for all items).
SKU is one of ABC, EFG, HIJ
SKU ON PROMO
ABC, EFG, HIJ
If customer selects SKU ON PROMO and if subtotal > $50,
customer receives free shipping. (Above sku total MUST ADD UP to $50 for customer to receive free shipping.)
Magento pop message should say code is valid.
If subtotal < $50 Magento pop message should say code is invalid.
NON PROMO SKU
Below SKU are not in promo e.g. AABB, BBZZ, TTTT
If customer adds NON PROMO SKU + Promo SKU (Promo sku add up to subtotal is over $50,
customer must pay shipping charges
Magento pop message should say code is invalid.