This could be store specific but I thought it was worth a mention. I was in the Ipswich branch of The Entertainer last week and they had a huge table of childrens books at £1 each but were also on BOGOF so cost 50p each!
There were lots of Lunar Jim ones which they have had for a while but they had also added lots of Bratz books. There were about 10 different reading books (rrp £3.99 each) and various activity sticker and activity books (rrp £2.99-£3.99 each).
I thought these would be great for birthday presents or party bags - at 50p each you can't really go wrong!
Couldn't see any online so would probably depend on what your store has left in stock as to what's included near you!