Cost-of-living price check · Costco Westgate vs Bunnings Westgate
WD-40 at Costco: Save on the 3-Pack, or Split It on eolma
WD-40 is one of those household products you eventually need, but buying three bottles at once can feel like overkill. A September 2026 price check at Costco Westgate shows why bulk buying can make sense and how eolma can help when you don't need the whole pack.
The headline comparison
Costco's WD-40 Non-Aerosol Trigger Spray is sold as a 3-pack of 330 mL bottles for $26.99. At Bunnings Westgate, the photographed 330 mL bottle was $15.98 each.
Comparing the same volume, three Bunnings bottles would cost $47.94. The Costco 3-pack is therefore about $20.95 less for the equivalent 990 mL, based on the prices shown in the September 2026 store photos.
| Comparison | Costco | Bunnings |
|---|---|---|
| Pack size | 3 × 330 mL | 330 mL |
| Total volume | 990 mL | 330 mL |
| Price | $26.99 | $15.98 |
| Price per 100 mL | $2.73 | $4.84 |
| Cost for 990 mL | $26.99 | $47.94 |
On a like-for-like volume basis, the Costco price is approximately 43.7% lower per 100 mL than the Bunnings price shown in these photos.
The shelf check
The photos behind the numbers
These photos were taken at Costco Westgate and Bunnings Westgate in September 2026. Store prices and availability can change, so check the shelf price when you shop.
The bulk-buying effect
The catch? You have to want three bottles.
This is where bulk buying can get interesting. If you already know you'll use WD-40 around the house, garage, workshop or garden, the three-pack gives you a lower unit price and a spare bottle for later.
But what if you only need one bottle? Buying three just to get the lower price isn't necessarily useful. You end up storing the other two bottles — or buying more product than you actually need.
A different way to bulk buy
Buy the Costco pack. Split the savings.
That's exactly the kind of situation eolma is designed for.
If three bottles are more than you need, find other nearby shoppers who want WD-40 too, split the Costco pack and share the cost. One person doesn't have to take all three bottles, and the group can still benefit from the bulk price.
Beyond WD-40
Small savings can add up
A saving of a few dollars on one household item might not seem significant. But the same idea can apply across hardware, household supplies, groceries and other products that are sold in quantities larger than one household needs.
The goal isn't simply to buy more. It's to make bulk pricing work for people who want the lower unit cost without necessarily wanting the entire bulk quantity.