I found this drink a few months ago when I was horrified at Cadbury's Highlights (which I'd used for a long time) reducing their jar size and keeping the price the same. Requires a bit more stirring than more expensive brands but I think that's a small price to pay for such good value.
This works out at 20p/100g - a fraction of most of the competition. You may be surprised if you give it a try. I was.