When I lived in the Shetland Islands there was a lot of difference in the prices you paid for essential items, between the main town and the small islands shops. The story goes that one of the owners of one of these country shops, the one that was reputed to have the highest prices of the lot, made a very rare visit to the 'big city' (Lerwick). He was asked what percentage of mark-up he used when pricing his goods. He replied that he did not believe in or bother with all this percentage nonsense. He went on to say that, if he paid œ1 for it he sold it for œ2 and if he paid œ10 for it he sold it for œ20!