As per title, Becks Bier, 12 x 440 ml Cans is £7.70 at Waitrose and Ocado. This is 4 packs on a 3 for 2 offer, so you buy two of the 4 packs and get the third free.
This works out at £1.46 per litre / 83p per pint. Okay it's cans, but it the cheapest Becks you can get at the moment. This is imported beer, but I believe it is canned over here.