Bought the last lot at Coles, $2.50 for one litre, bought three boxes. (6 in a box)
Nothing but 100% pure Coconut water:
http://www.purecocobella.com/coconut-water-range/straightup/1000ml/
Regular price is $5 around here still cheaper than tap water from the servo.
I can buy it from the fruit shop down the road from my mum's place at the Gold Coast for around $2.50 per litre if bought by the box.
Still tastes better to crack your own coconuts IMO, again around here they are about $4 each, in civilisation about half that.