If you need the normal 3 DVD triology edition, its £7.99 @ Zavvi
Due for release on 20/10/2008
Presented by filmmaking legend Steven Spielberg, directed by Oscar winner Robert Zemeckis, and starring time-travellers Michael J. Fox and Christopher Lloyd, the phenomenally popular Back To The Future films are back with a brand new bonus disc packed with additional footage. This 4-Disc Ultimate Edition contains the three movies and over 9 hours of bonus features to let you re-live the adventure time and time again!