I noticed this by chance while doing my shopping, didn't expect to get it delivered, but my shopping just arrived and the 2.2kg tin really was only £2.24! Expiry date on tin is December 2007!
You can find them on the Biscuits, Snacks and Sweets Shelf > Christmas > Seasonal Twistwrap Chocolates. They also had a 1.2kg tin of Quality Street for £1.49, but this wasn't in stock at my store.
I guess it helps that my store is online only.