http://www.greenmangaming.com/deal-of-the-day/ use code SPOOKY-TREATS-GMG20X to get the complete valve pack (inc CS GO) for £10.
or use this code
SLICKD-EALS22-OFFGMG
and get it for £9.75

its all one key apparently
if you add it to an account which already has the games it doesnt give you a gift of the ones you already own you just lose those games
tempted to get a smurf, use this and buy cod from russia for £10