I was looking through the upcoming releases on Blu-Ray and they have some pretty cheap pre-orders and you can use quidco or student discount to make them even cheaper...here are a list of films that I found...
Dark Knight £14.99
The Mummy 3 £14.99
The Incredible Hulk £14.99
Hellboy 2 £13.99
Star Wars The Clone Wars £14.99
It's nice to see that the Blu-Ray discs are coming down in price! Gonna get a couple of these for Christmas