I know there are a few threads at the moment about Avatar and District 9, but just wanted to give a tip and share my experience.
I picked up Avatar yesterday from Sainsburys. It was £14.99 but I had a couple of Nectar Rewards points so it cost me £10.
However, at the time of purchase, I was given a £3 off any chart Blu Ray. Currently, District 9 is only £10 at Sainsburys (http://www.hotukdeals.com/item/657701/various-blu-ray-10-sainsburys-from-).
Not a deal, more of a tip, but just in case anyone did purchase Avatar from Sainsburys yesterday and had missed the District 9 post.
Please note there are a number of Chart Blu Rays for £10 at Sainsburys currently.
Hope this helps some people.