Joining Costco Cost Me $60 -- but I Saved Nearly $100 My First Visit. Here's How

Folks love Costco. Some are even downright passionate about it. And after purchasing my own Gold Star membership just recently and making my first trip to the store, I'm starting to see why.

I was excited about my first shopping adventure at Costco. So excited, in fact, that I probably went a bit overboard and ended up leaving the store with a total tab of more than $250. Eek. But as it turns out, I managed to save almost $100 in just one visit. That means my $60 annual membership more than paid for itself already. Outstanding! Find out how I calculated my savings and how you can form your own cost comparison to discover how much Costco is saving YOU.

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Per-unit costs are the ticket

Costco is known for selling goods in bulk (though not all of Costco's perks come in the form of bulk goodies). So while you might pick up a package of 20 to 60 dishwasher tabs at your local grocery store, at Costco you can find packages of more than 100. But it's not the size of the package that matters, it's the value you get from buying items in bulk. You can definitely save by stocking up on household goods and shelf-stable pantry items that don't expire (or at least don't expire quickly) at Costco.

To illustrate this, I've calculated how much a selection of items cost per unit (a single ounce, single sheet, single pod, etc) at Costco and at my usual grocery store (Meijer). Then, I calculate how much the same number of units I got from Costco would cost at my regular grocery store. This determines how much I saved per item by buying in bulk. You can do this for each item on your own grocery list to calculate your total Costco savings.

For simplicity's sake, I chose just 10 staple items off my receipt (and STILL managed to come out to nearly $100 in savings!). Note that in my comparison, all Costco items purchased were the Kirkland Signature store brand, so when possible, I compared them to Meijer's store brand item prices.

That's $96.24 in savings, on just those 10 items! As you can see, my savings on some items – like the rotisserie chicken and extra virgin olive oil – were negligible, but they were savings nonetheless.

Other items are just far and away a better deal at Costco, like laundry pods, dishwasher tabs, and trash bags! You don't have to worry about these items going bad, so if you've got the space, it makes sense to stock up and reap the savings. Any extra cash you save at Costco can go to pad your emergency savings fund or to shore up your savings account.

My final mentionable point from this cost comparison is that while I said above that I compared prices using Meijer-brand items, Meijer does not carry a store-brand laundry pod, so in this case I chose the cheapest option I could find at the store. This turned out to be Tide brand pods in Original scent, 112 count for $27.99, or approximately $0.25 per pod.

Calculate your own cost savings

Figuring out how much you're saving (or could save) by shopping at Costco is easy. To calculate an item's per-unit price, just take the item's total price and divide by the number of units. For example, for 48 ounces of raw honey from Costco, I take $12.99 and divide it by 48. That gives us a per-unit cost of $0.27 per ounce. Meijer charges $11.99 for 32 ounces, so that works out to approx $0.37 per ounce.

Your calculations could stop there, as you can already see that each unit of honey at Costco is cheaper. But to determine how much you saved by buying all 48 ounces of that honey, you'd have to take your number of units (48) and multiply by the per-unit price of your comparison, in this case, $0.37. That tells us that to buy 48 ounces of comparable honey at Meijer, you'd spend the $17.76 you find in our "Meijer equivalent" column in the table above.

If you're like me, perhaps math is not your favorite subject, nor a particular strong suit. But these calculations are fairly simple to do, and they can be incredibly eye-opening to show you just how worth it your Costco membership can be for your family's personal finances.