Greetings everyone, I think this has to be some sort of pricing error at Coles, haven't seen it this cheap in forever.
Coles have the larger 473mL versions of Red Bull Original at $16.30 on sale, but they also have an online only special which is 2x for $13.50 ($1.68 per can / $3.65 per litre).
Compared to recent specials, the cheapest I can see is $4.49 per litre at Amazon with S&S. Seems pretty damn good and also is eligible for the container refund scheme, bringing the total to $12.70 ($1.58 per can / $3.35 per litre) for CRS states.
Note: This is Online Only, so will need to spend $50 as a minimum to C&C. You can add as many packs greater than 2 and each of them will be $6.25 each for the 4 pack.
Another good deal for CRS states is 2x Pepsi Max 30 Pack 375mL Cases $30 ($15 Each).
Check your Flybuys offers to see if there's any promotions to stack with :)
Stack with coupons such as 10% off $180 Spend with CYBER10 and/or "CLICK10" for $10 off $100 spend on first C&C order.
For those that want free delivery, there is a 1-month free trial to Coles Plus which has free delivery > $100 spend.
As always, enjoy :)