I finally decided to venture into The Greener Grocers, a supermarket that replaced Franklins at Maroubra Junction, and was surprised to see some products with prices less than the 3 major supermarket brands.
3L fresh milk with the brand "Budget" ? cost $2.69 but I haven't seen this brand elsewhere (…nor this supermarket).
Although I've never tried it they had spice chai instant tea for $4.99 that wasn't even marked reduced ($7.29 at Coles for the same container). They also had cheaper things you normally find in ethnic food stores such as random 2 kg yoghurt containers and huge bags of rice.
Might be worth keeping an eye on for Maroubra residents that don't want to venture out to Eastlakes.
Definitely a good place to buy a bargain.
My dad walked out with 3 short dated (one month left) 24 packs of Pepsi Max for $2 each once.