It certainly pays to shop smart and pay attention to your receipts and the cash while they're scanning.
I just came across this receipt from a couple weeks back while cleaning out my plastic grocery bags before putting them back in the car. I have bins full of them as I never used to throw them out. So this was from Freshco, I bought 18 items and every single one was on sale. Total sale was $63.69, total savings was $50.52 and I also earned $8.50 in points. Bottom line is that I saved just over 51% on the regular price of 114.21. I always stock up on items I regularly use when they go on sale.