It's happened so many times, the price at the till doesn't tally with the price on the shelf. When you query it you see that the item at the price you thought it was is slightly different to the one that has the price shown. This is done with lots of products. For example yesterday I picked up a hair dye which was priced at £4.99, but at the till was £6.50. On checking, the assistant said "no the £4.99 one was only for a particular shade" (which incidently had sold out), we eventually found the £6.50 label but it was nowhere near the product. Aibu to say that these are deliberate dirty tactics by the supermarkets. There are loads of other instances like this too numerous to mention.