I thought this was a good deal, a bargain in fact! Free standard delivery!!
Three top blockbuster movies for £7.50 then when the 10% off code "PX8P" which others here have quoted is used, it brings it down to £6.75.
You can even purchase without registering with Debenhams. I've done this myself, and it all worked fine and i still got the £6.75 price.
It's even cheaper than the Debehams dedicated entertainment section price of £9.99 price which came up when I looked there.
I think you can go through Quidco for extra cashback as well.