Sainsbury's cheap PNY cards are in packaging very similar to this ...
Can't miss the 4GB as are 'Raspberry Pi apt "shocking pink" 8GB bright blue. In my local store they moved from the CD/DVD media area to the 'cheap electrical' section where the Masterplug kit can be found. There weren't a lot when I grabbed mine - I didn't believe the price and was half expecting a trip to the customer service desk.
SD4GBHCCOLP-EF, barcode 3 536401 531463
SD8GBHCCOLB-EF, barcode 3 536401 531470
Plenty of references ( and far higher prices ) on t'web but all out of stock so would guess it's a limited end of line deal.
The single USB Masterplug sockets were hanging on a vertical plastic strip of 10, 5 white, 5 black from the labelling.