The better quality kits retail in the UK for over £11 for a 5 gal batch, and then you may need to add extra sugar. One of the best kits I've heard of retails at about £17 and needs no extra sugar. My last batch was pure apple juice (not from concentrate) and cost £16.79. I'm happier using straight apple juice.
Obviously apples are out of season in the UK now so the only sensible option is to get down to a supermarket for juice. Pressed apple juice (i.e. not from concentrate) in cartons is available in just about all of them - you just need to look out for it. Average price at the moment seems about 79p a Litre.
Last batch I've made (the Cider Morello in my sig) was using 'cloudy pressed apple juice' from Lidl.
If you were nearer the Buxton/Matlock end of Derbyshire I'd have recommended the HBS in Stockport (on the main A6 into Manchester) for equipment (but ring them first to check they have what you want). I haven't been in for at least 5 years but I know they're still going. Depends if you fancy the drive I guess.....