I was checking out the new Target at the Sunnyvale Town Center. Since it featured a grocery section, I wanted to see how competitive the prices were with the places I usually frequent. Target was selling an 18 oz. box of Frosted Mini-Wheats for $3.09 or $0.172 per ounce. Wal-Mart was selling the same size box for $2.33 four months ago. So, Target sells Frosted Mini-Wheats for a bit less than Safeway, but a lot more than Wal-Mart or Costco.

If I wasn’t paying close attention, I would have completely missed this one. At first glance, I thought that Target sold an individual pack of Cetaphil while Costco sold a twin pack.

However, upon closer inspection, I discovered that the Target was selling a 16 oz. bottle, while Costco was selling 2 x 20 oz. bottles. Anyways, Target sells Cetaphil Moisturizing Lotion for $0.559 per ounce while Costco sells it for $0.388 per ounce. If Costco sold a 16 oz. bottle at $0.388 per ounce, the total would be $6.21, quite a bit less than the $8.94 Target is charging.

Comparison shopping within a store is pretty easy with a calculator in hand. However, unless you store all your prices in a spreadsheet, this task can be challenging because quantities for even standard goods may differ.

Case in point: Brita water filters. Costco sells a 10 pack, Target sells a 6 pack, and Wal-Mart sells a 4 pack. Wal-Mart sells a 4 pack of Brita filters for $19.44, or $4.86 per filter. The best price from my last price check was $4.199 per filter from Costco. However, Wal-Mart did edge out Target be a few cents per filter (i.e., $4.86 v. $4.948). However, I spotted a 5-pack of Brita Water Filters at walmart.com selling for $39.98, or $7.996 per filter! The lesson here is to not assume that the in-store and online prices are the same, or that online prices much be cheaper than within a bricks and mortar store.

A few weeks ago, OSH was selling an 8.7 oz. bottle of Shout Gel for $4.99. So, was this a “great value” as the sign proclaimed?

Target, which used to carry Shout Gel, did not have the product on its shelves. Instead, it stocked an 8.7 oz. bottle of Shout Advanced Gel for $2.64. Between the two, Target offered a greater value.

Target sells a 30-count box of Refresh Plus single use vials for $6.99, or $0.233 per vial. Costco sells a 100-count box of Refresh Plus single use vials for $18.39, or $0.184 per vial. If you use a vial a day for an entire year, Costco will save you $17.89. That’s IF you use a vial a day.

Costco regularly sells a 15 lb box of Oxi-Clean for $16.99. Currently, Costco has an instant manufacturer’s rebate of $4.00, which drops the price down to $12.99. So, if the sales prices at traditional retail stores are almost as good as the regular prices at Costco, how good are Costco’s sales prices?

Mind you that this is not a mail-in rebate or one that requires a coupon in hand. The discount is automatically taken at the register. Since, 1 pound = 16 ounces, Costco sells Oxi-Clean at $0.071 per ounce (regular price) and $0.0541 per ounce (sale price).

Target sells a 6 pound tub of Oxi Clean for $8.49, marked as a temporary price cut. The regular price is $9.99. So, Target sells Oxi Clean at $0.104 per ounce (regular price) and $0.0884 per ounce (sale price). Currently, the OxiClean site has a $1.00 OxiClean coupon for any OxiClean powder (56 oz. or larger). Since 6 pounds = 96 ounces, the tub qualifies. So, at $7.49, the unit price is now $0.0780 per ounce, which isn’t even better than the Costco regular price. The killer deal is that the Costco sale price is over 30% the Target sales price + coupon! For the same amount of stain remover, 6 lbs. at the Target sales price with coupon is $7.49 and 6 lbs. at the Costco sales price is $5.19.

Granted, whether you are buying 6 lbs. or 15 lbs. of Oxi Clean, either size will last a long time. While you do save $2.20 per 6 lbs., saving a couple dollars a month isn’t the same as saving a couple dollars per week (or per day).

Costco sells a 10 pack of Brita filters for $41.99. The math is really easy for this one. $4.199 per filter.

Target sells a 6 pack of Brita filters for $29.69, or $4.948 per filter. If you change your filter every two months, that’s six filters per year or an annual savings of $4.50 by buying in bulk from Costco.

Another Target v. Costco showdown. This time, Target is having a sale!

Target sells an 8-oz tube of Crest Whitening plus Scope toothpaste for $2.99. Regular price $3.79. Is this sale item a bargain or not?

Costco sells 5×8-oz. tubes of Crest Whitening + Scope toothpaste for $12.99. If you buy 5 tubes from Target, the sale price is $14.95 while the regular price would have been $18.95.

So, even when Target has a product on sale, Costco’s regular price beats it, but only by $1.96 provided you are willing to buy in bulk.

I’m standing in the dental products aisle at Target. I can buy 1x40M pack of Crest Glide Deep Clean Floss for $3.54 or a 2x40M pack of Crest Glide Deep Clean Floss for $5.99. I don’t even need a calculator for this one. Buying the value pack costs around $2.995 per pack.

Now, Costco sells a 6x40M pack of Crest Glide Deep Clean Floss for $12.99, which is $2.165 per pack.

Costco wins. 6x40M is around 787 feet of dental floss. If you use 1 1/2 feet of floss a day, that 6 pack will last you almost 1 1/2 years. So, while you will be saving 28% by buying a 6×40 pack instead of 3 2x40M packs, in terms of dollars, you’ll only be pocketing a difference of $4.98 excluding taxes.