FWIW, I just checked my Shoprite register receipts, and I have noticed that the $ amount that is considered towards fulfillment of the $500 threshold is the $ amount purchased at Shoprites prior to your use of whatever manufacturer coupons you might have.

Although this is not all that much, it is nice to know that the $ figure that is applied is not the final total that you pay at checkout, rather it is that amount prior to coupon deductions (and at my local Shoprite, that = Double coupons up to .99!).