Just received the milk letter from school. Not sure if milk prices vary by area/school, but I'm being asked to pay £18.25 for the Autumn term. That's for a 189ml carton of semi-skimmed for 8 weeks, which works out at a whopping £2.42 per litre (£1.37 per pint) of supposedly EU-subsidised milk 
Beyond the maths, though, I can't even begin to explain just how much school milk goes to waste. I'm a TA and in my KS2 class, only three children are on the milk list... yet they never EVER drink it, and even though we do offer it to the rest of the class, there are rarely any takers. In Reception, where more than half the class are on the milk list, they are regularly chucking whole packs of it. And that's not just the milk, it's all the packaging and the plastic straws, makes my heart sink 
The odd thing is, I've always asked my kids whether they want milk before renewing. And they'd always said yes. But having seen all that waste, I thought I'd go a bit further and ask it they drink all of it or just take a sip and put the rest in the bin. Guess what the answer was.
So last term, I bought them a small thermos flask each and started sending milk in with them. This lasted all of 2 weeks, in which time they were coming home with the flasks still full. Lesson learnt 
I guess what I'm trying to say, grill your kids before you pay! And if you don't think they actually drink much of it, save your money and the planet. They'll drink some at home if they want to.