Was in Wilkinsons in Aylesbury and noticed these, which I thought were a great price at £3.99 (Sorry it is actually £3.98, a penny cheaper!), considering an almost identical set in Argos is currently £11.99 (using their picture).
The set includes:1 x Single Duvet Cover & 1 x Matching Pillowcase
Available in Pink or Blue, with each set having a different shade of the colour on it's reverse side, so just flip over for a change.
They also had some co-ordinating items for these sets, such as curtains, which if I remember correctly were £10 a set
Plain & basic sure, and I'm sure of the usual 50/50 poly/cotton mix, but for only £3.98 well worth having, even if only as a spare set.
Haven't found this anywhere on Wilko's website, so instore only, and would assume nationwide, as it was printed POS detailing the offer.