One thing that you learn when you become a parent is that the cost of “stuff” for babies and kids can add up pretty quickly. As a result, many of us are always trying to get deals on these things to help keep costs in check.

But how do we know we are REALLY getting a good deal? I remember once talking to a mom friend about how much I love Costco because the savings on the diapers alone make the membership worth while. She said “nah, I always just buy the diapers on sale at the grocery store.”

And here was her mistake. I find that stores are always tricking us into thinking that because we are getting something “on sale” that its a deal and that we are saving money or if the price is lower. And what makes it even more confusing is that the package of one brand often doesn’t contain the same amount of product as a comparable product.

This is why you can’t look at how much the price is “on sale” and compare that to the original price or even the price of another brand, but how much the price is PER UNIT at that location as compared to the price PER UNIT at another location or the price PER UNIT of a comparable brand (say, Pampers vs Huggies).

So to really know if you are getting a “deal” or paying the lowest amount is to look at the unit cost. And the kicker is, that many store actually post the unit price on the price label on the shelf! So the diapers that are “on sale” may still be more expensive than a comparable brand at the regular price or the same brand of diapers at the regular price in a different location.

Here is an example of 3 stores selling the same brand and size of diapers (all prices taken from the store websites or store visits).  At first glance, Costco seems the most expensive because the price in total is $48.99. But because there are more diapers in the package they sell, the unit cost (i.e the cost per diaper) is actually the lowest.

You may think to yourself, ok but is $0.02 or $0.09 really worth the hassle? Well consider it this way – what is the cost difference per month? Say a 20 month old uses on average 5 diapers a day. That is 150 diapers a month. This is what the difference per month would be:

So that is almost $15 per month difference for the cost of the exact same product. Imagine doing this with just a handful of products that you buy regularly and the impact on your budget.

That being said, I’m not saying that Costco is the solution. There are things even at Costco that aren’t always the cheapest option. Plus, even if something MAY be cheaper because it is bought in bulk, it doesn’t always make sense – if you only eat quinoa once in a blue moon, there is no point to buying a 2KG bag of it just because you save $0.05 per gram or whatever.

But next time you go shopping, remember, all you do is just take the total price and divide by the number of items/weight (grams/oz) in the package to get your unit cost – and use THAT as your basis for comparison to see if you are REALLY getting a deal and saving the most money.

Happy saving!