Camelbak Charge 2L hydration pack for $73.49 delivered from wiggle.co.uk
These Camelbaks are very good. I have a 1.5L that I've abused enduro riding for near on 4 years now and its still alive. Very well made.
Average price you'll pay for the 3L one in oz is around $107 or so. Cell Bikes have this for $89 in their sale but tack on another bit for delivery $5 up and the wiggle price looks very good especially seeing as its delivered.