Great deal, these are now reduced from £29.99 to £14.99, and it's buy one get one free so you get 2 duvet cover sets for £14.99!
There's several other designs in the offer and for the same price or cheaper:
Taffeta Hearts Double Duvet Set
Plain Dyed Super Kingsize Duvet Cover Set - White
Shanghai Embroidered Double Duvet Set - Navy or Fuschia (£13.99 + BOGOF)