So Good Soy Lite 1L, 3 for $5. It's normally about $2 each so save $1 by buying multiple and stocking up.
Also at Canberra store (not sure about others): So Good Soy Milk (regular) for $1.79, normally $2. Freedom Original Wholebean Soy Milk, $1.99, normally $2.19. This latter one seems to me richer and tastier than So Good, but the nutritional information suggests otherwise!
http://www.menshealth.com/nutrition/soys-negative-effects