Juicing carrots

I'm still trying to find the best fruit and veg to juice in terms of mL per pound. Carrots seems like quite a cheap veg to juice. For 463 grams of carrots (0.69/kg) I got 255mL, this means that it is £1.17 per litre. Almost half the price of juicing a pear.
On a related issue, did you know that the government is charging 17.5% on natural juice and smoothies whereas foods (burgers and ready-made pizzas) are not taxed. It doesn't quite seem right that good healthy juice is taxed the same as coca-cola. They are suppose to be encouraging use to eat and drink healthily.
carrots VAT tax juice smoothies