Recently my 5 year old Camlebak bladder sprang a leak on one of the seams – being a frugal chap I looked into alternatives and found this:
http://www.clasohlson.com/uk/Asaklitt-2-Litre-Hydration-Bladder/31-2160
Bladder, Hose, neoprene cover for the tube, the tube and a decent bite valve for about the cost of a Genuine(tm) Camelbak(tm) bit valve.
It’s decent quality too, admittedly the first one they sent me leaked like a sieve around the bit where the hose meets the bladder – but I’m 99% certain that was down to it being left 4″ under a hot light in my kitchen for a week… oops – anyway good old Clas replaced it without fuss, and a few days later a nice Scandinavian sounding lady called me up and refunded me the cost of the postage back to them – lovely people.