*ADDED* It seems only the blue duvet set is the ones misspriced/ on offer.
The barcode to watch out for is: 5 051008 567090 ***
Went into my local Tesco (Ilkeston) and picked up a Tesco Reversible Double Duvet Set which was supposed to come to £8 but upon pricing on on the till it only charged me for £1.21! Not sure if this is a local or Nationwide pricing error but just thought I'd let you know there is a amazing deal to be had if you manage to get it!
If you go to the tills and charges you full price you always have the right to go straight to customer services for an exchange!