Nearly all grocers in England (Asda, Tesco, Sainsburys, Morrions) will have a weekly offer on crates, you can nearly always find 20 crates of stella for 20 quid (20x400mlx2). I guess these aren't available in Scotland? You only really pay over a fiver a four pack when you're in a rush at the co-op or tesco express, if you're in the big store you'll change 4 stella to four kroneberg for 3.29 or whatever similar, on mainstream lagers anyway