What the heck is an iysles? Do you mean AISLES? And they don't. They put the BEST deals on the very top and very bottom shelves. The end-cap deals are only there to lure you into buying more. Look up or look down for better deals. (It's an old marketing technique.) I'm guessing you are in UK so have been 'edukatd' by 'teachers' who have never held a real job or worked in a real business .. so you won't know any of the basics of the market place, let alone how a business operates ... Look up the definition of Capitalism, then Advertising, & go from there .. HINT - Tesco is a business operating in a competitive market and would like to sell as many high margin goods as possible to their customers .. Further hint - customers are unlikely to buy expensive goods if they see a cheaper alternative FIRST .. Final hint - it's the same reason why they put the 'staples' (bread) at the back of the store and keep moving things around ..