You beat me to posting about this 
I read the article and it seems they try and have a managers special section for the more "upmarket" items. The problem lies within their tag line of Everything £1.
Seems you cant say that and then have a product marked at £8.99 - why they dont just change it to most things £1 but then that involves the consumer having to check how much something is, surely that won't take off ..........
Oh hang on, supermarkets have been individually marking things at different prices for a very long time!
Think the model is buy it in bulk and sell it cheap