Beer

So I'm looking at the beer shelves in Tesco deciding what to buy and the guy standing next to me lets out an amused snort.  I ask him what's amused him and he points out that they have Fuller's Honey Dew on two separate shelves.  One of them is of 500ml bottles at £1.  The other is of 330ml bottles, priced £1.33.  So you are paying a third more for two-thirds the amount.