My local Argos has a display stand of video games - X-Box, PS3, DSi ,Wii. I noticed it had Wii Fit for £34.29 - it's in the catalogue for £68.49, cat no 568/5970. I filled in a paper request form and took it to the cashier who asked for £68.49. I politely queried it and the cashier asked to be shown the display stand; then she spoke to a manager and came back to say they would honour the price and let me have it for £34.29. She said the display stand had only been out for a day or two and that someone from head office would catch it for this as it should be £68.49. As I was leaving I noticed the price was being taken off the stand!
It's probably up to the manager whether or not they will honour the price, and probably only one customer per store stands a chance of getting this before they change the price, but it may be worth a try at your local Argos if they have the display stand with the wrong price on it. So be quick!!