Some years ago, we bought several bags of Dynamic Lifter from Bunnings and happened to visit Big W on the way home.
Big W had 20 kg bags of Dynamic Lifter for less than we paid for the 17.5 Kg bags at Bunnings so we returned to Bunnings. They refused to beat Big W’s price on the basis the 2 items were not identical.
We returned to our vehicle and brought the bags back for a refund right on closing time, much to the considerable annoyance of the staff, and bought the 20Kg bags from Big W the following day.
On the other hand, when we wanted to buy 3 lockable metal storage cabinets some years ago, we checked the price at Bunnings and then at another hardware store who were considerably cheaper.
We returned to Bunnings with a copy of the brochure with the prices written on it. Bunnings called the other store to confirm the prices and sold us the cabinets for 10% less, so we saved a bundle.
In our experience, the bottom line is that the products must be identical, and Bunnings tries to avoid stocking identical products, hence the 17.5 Kg Dynamic Lifter.
When Masters started in Cairns, a young employee told us that they would not be stocking any of the same items as Bunnings so as to prevent having to honour the price guarantee which they had copied from Bunnings.