A few years ago The Man and I wrote a couple of posts about our favorite things to buy at Costco – you can read my 10 Things to Buy At Costco post here, and his take on The Man’s Guide to Costco’s Top 10.  These posts have been wildly popular! Well, actually, mainly his post :p And by wildly popular I mean people other than our family and friends read the posts and Google actually indexes it and points people to it! So that’s kind of exciting….nerdy, I know :D

Since writing those posts we’ve faithfully been shopping at Costco and purchasing our favorite products and deals. As life has gotten busier and fuller, we often have time to only hit one grocery store in a week. And too often we HAVE to pick something up from Costco, which leaves us with doing the lion’s share of our grocery shopping at the giant warehouse. Which leads us to a problem we thought we were immune too, but are now realizing we’ve fallen prey to instead.

Costco effect

The Costco Effect

Sounds sinister and deadly, doesn’t it? Well it can be – to your wallet and budget that is, if you’re not careful!

The Costco effect is just this – Costco has so many great products and deals for much cheaper than a lot of other stores charge and in greater quantities. However, as we’ve already established in our Costco posts, not EVERYTHING is the best deal – some things are definitely more expensive, even if you’re purchasing them in bulk.


If you end up doing a lot of your shopping at Costco and don’t just buy the good deals, you’re suddenly spending more money than you need to. Even though in your head you’re buying in bulk and feeling like you’re getting a good deal, you’re actually not.

The second part of the problem is that all too often, fresh produce bought in bulk goes bad before it’s eaten, which leaves us wasting a lot more than we’re saving. And if you have a lot of something, you tend to consume a lot more of it, when maybe you actually didn’t need to eat 3 oranges in one day.

The third aspect of the Costco effect is when you see something that is a good price, suddenly you need it and buy it, even though before you saw the “great deal”, you didn’t need it at all. But we justify the purchase because the price is right. We see this happen the MOST with clothing items at Costco, especially since they carry a lot of name brands for seemingly good prices.

Costco Urban Star jeans

So how do we avoid falling into the Costco effect trap?

  • Use our Top 10 items to buy at Costco posts here and here to determine what is actually a good deal and what isn’t, and when to buy – for example, produce is NOT a good price during the summer or harvest months at Costco. The farmer’s market and local grocery stores are much cheaper! But in the cold winter months, Costco’s prices are hard to beat.

Market fruit

  • Set boundaries and a budget for your Costco shopping trip. Only buy the things you absolutely “need” to buy at Costco and can’t get for a better price elsewhere.
  • Go in with a set list and unless something is on the list, don’t buy it! Have someone keep you accountable to sticking to the list. We use Trello on our smart phones and share the list between our phones to keep track of the items we typically purchase so we aren’t adding any unnecessary things.
  • Only visit Costco once a month! Previously we were hitting Costco almost once a week and spending at least $100 each time. Now we do one big shop a month at Costco (with a mid-month stock up on coffee beans :D) and if we run out of something before the next shop, then we make do without it. Since doing this we’ve spent hundreds of dollars LESS on our grocery bill. It’s shocking really how quickly things add up at Costco and how quickly they run out.

Costco dairy

Here’s the list of our absolute “must have” Costco items which we stock up on once a month. It’s slightly different from our Top 10 lists, but these are the items we can’t get for a better price anywhere else or aren’t willing to compromise on in quality:

  • Coffee beans
  • Milk
  • Cream
  • Eggs
  • Butter
  • Cheese
  • Toilet paper
  • Bulk almonds and chocolate chips
  • Flour
  • Frozen fruit and vegetables
  • Flavoured and Greek yogurt
  • Bacon
  • Deli meats

Have you ever experienced the Costco effect? What are your essential items to purchase at Costco?