Optifast shakes on sale at Amcal - $35, which is cheaper then most places (Normally around $37), this is for the 12 pack of 54g shakes and not the 20 pack of 40g (These taste slightly better and contain more per pack).
Cashrewards coupon code gives free Shipping when you spend over $40 (2 boxes of shakes)
Life coupon gives 10% off
I talked my partner into trying bulk nutrients meal replacement shakes instead of these weight loss shakes which are mostly just flavoured skim milk powder. She has half a serve which gets you 32 serves/bag ($1/serve if you get 2kg delivered) and apparently it's filling and tastes good. Can't see any kj info on these but the bulk nutrients are about 800kj with half a serve (1 scoop) and 200mL of skim milk and obviously less with water.