If you want to kickstart of weight loss/diet habit, my recommendation would be something extreme to detox (Cabbage Soup Diet or similar) for 7 days, then followed by a low GI healthy eating plan.

If you are keen on a "shake" based diet (that is prescriptive, which may help you keep on track perhaps?) then this is what I have done in the past for a lot cheaper, and it works really well!

For 2 meals a day, have this "smoothie"

250ml Skimmed milk
2 heaped teaspoons of Phylissium Husks
1 heaped teasoon of InLiven (probiotic)

Blend together with ONE only of the following:

1 small banana
2 fresh apricots
1/2 cup of berries
1/2 cup watermelon
1 large Kiwi (peeled)
I medium ripe pear, peeled and cored
1/2 cup strawberries

Drink it quickly!

Then for your other meal, 200g protein (grilled, steamed or baked) served with as much veggies or salad as you like. (No dressing or butter etc).

HTH

(Disclaimer! I have lost weight very sucessfully and healthily doing this. But as with all things "diet", as soon as I eat "normally" again I stack it back on!)