As per title, you can currently buy 8 x 500ml bottles of Czech Lager for £6.72 at Marks and Spencer. This is 5% ABV and is from the Bohemia Regent Brewery.
The bottles are £1.49 each and along with all other bottles of beer in M&S are on a 4 for the price of 3 offer. In addition, if you buy more than 6 bottles, you qualify for the 25% wines discount, which brings the price down to £6.72 for 8 bottles.
So this works out at 84p per bottle / £1.68 per litre / 95p per pint.
The also have 500ml bottles of Winterfest Beer at the same price if you can find a store with stock.
This double discount applies to all bottled beers and amounts to a 44% discount, so even if your store has none of the £1.49 beers, there's some real value to be had.