Depends, your local CDCs are permitted to sell CD products for whatever they want, within certain limits. It also depends on what plan you are on, and whether you need 3 or 4 meals per day.
My CDC charges £1.70 for sachets and £1.95 for bars. If you are under 5' 8" then you'll need 3 meals per day; over this you'll need 4 (think that's the height range anyway).
So if you only have sachets (shakes, soups, porridge) you're looking at £35.70 or £47.60 depending. Add in bars or tetras and the price will be more.