2 grams of chronic; mid-high quality herb for £20 (a '20' bag)? Not really premium quality stuff, but still potent. I always thought a '20' bag had at least 2.5grams, even if it's the best quality stuff around.
thats a bit steep.. £10 a gram would be too expensive for me, even if it was some chronic. My current Weed dealer sells a 1/4 ounce for £50, which is considered a little bit expensive, but still not too bad considering the quality of the bud. Still a bit cheaper than what you're paying dude. Try haggle or find someone cheaper.