SIS GO isotonic 60ml (6pack) currently BOGOF best price I can find.
Some other decent offers to on their website at the minute
SIS GO energy bars 65g 24 pack with 33% off now £21.09
+ FREE delivery if you spend over £10
+FREE 800ml SiS Cycling Drinks Bottle – Narrow Neck if you spend £25http://www.scienceinsport.com