Asda are selling 35g (ie small) bars of Lindt Excellence Dark Chocolate with 70% cocoa solids and Milk Chocolate for 10p. I asked if there was a limit of purchases per customer and was told there is not.
(picture is of 100g bars, couldn't find a 35g image)
My local store is Linwood Rd, Paisley....can't see it online so not sure if it's nationwide.
Best before date is 04/09