You can get the complete 8 film Harry Potter collection for £17.99 delivered from Amazon at the moment which is al all time low Amazon price. If this wasn't already a good enough deal you also get a free £1 credit to use in the Amazon MP3 store thrown in as well.

Films included :-
Harry Potter And The Philosopher's Stone (2001)
Harry Potter And The Chamber Of Secrets (2002)
Harry Potter And The Prisoner Of Azkaban (2004)
Harry Potter And The Goblet Of Fire (2005)
Harry Potter And The Order Of The Phoenix (2007)
Harry Potter And The Half-Blood Prince (2009)
Harry Potter And The Deathly Hallows: Part 1 (2010)
Harry Potter And The Deathly Hallows: Part 2 (2011)