Is there anywhere to buy this?

Im from the UK and saw this movie a couple of years ago on TV and loved it. I found it on Video and I was looking for it the other day but it seems I've lost it.
Like I said I really love this movie and its one of those movies I grew up watching. I really want to buy it but Amazon has it on dvd for 45 pounds which is way too overpriced. I was just wondering if any one knew of a good place to get cheaper dvds?