HOUSTON --Buying groceries at the drug store often means you pay big for convenience, but that's not always the case. It could actually be a huge money saver. The reason why drug stores may be a great deal is because they offer incentives -- basically, rewards that act like cash. But are the deals any good? We decided to test this theory and went shopping to check it out. When you think of milk, eggs and bread, you probably don't think of the corner drug store. But maybe you should, says Super Saver Erin Libranda. "If you go in with a plan and you know things are on sale, have coupons, Register Rewards, Extra Care Bucks, you can come out of there way ahead than buying at the grocery store," Libranda said. Register Rewards, Extra Care Bucks, coupons -- they sound complicated, but Libranda says it really isn't. The actual ad will tell you exactly what's on sale, where you can find a coupon for it and if you can score rewards bucks back. "It's in the ad. It shows it's no big secret, exactly," Libranda said. So we headed to CVS and Walgreens to test this theory. For each sale item, the store spells out your savings and bright yellow tags alert you to the deals. At Walgreens, the Ocean Spray juice is on sale for $2.99 but you'll get $2 back in Register Rewards, making the juice actually 99 cents. At CVS, Kraft Deluxe Macaroni is on sale two for $6. Not a bad deal, but with register rewards, you get $3 back, making this deal actually two for $3. Right now General Mills cereal is on sale three for $10, but if you buy three for $10, you'll actually get $4 back in rewards bucks, making that three for $6. On top of that, if you have a coupon you can save even more money. So the total cost of one box of cereal costs $1.66. At checkout, we purchase several groceries, all sale items. For this purchase we used two coupons. Our total out of pocket expense was $19.87; but after we paid, instantly we got $5 back we can use immediately. At a local grocery store, we picked up the exact same items, same size and we use the same coupons but our total out of pocket was $23.47. Remember our exact drug store groceries totaled $19.87 and we got $5 back. That's a savings of $8.60 if you shopped at the drug store. So the bottom line: shop sale items at the drug store and combine coupons to save even more.