If you're going to keep cancelling decent series before concluding the story, save yourselves even more money and don't bother releasing them on DVD.
I have got so fed up with buying series of my favourite shows on DVD, only for it to be cancelled, that I now no longer buy ANY show on DVD until I know that the story has been completed.
Sci-Fi UK advertised My Own Worst Enemy on DVD after the final episode last week... but what's the point in buying it? It's like buying a book when you know the last few chapters are missing. Similarly, I will not be buying Knight Rider, Terminator: The Sarah Connor Chronicles, The Riches, Standoff nor any of the other cancelled shows I've enjoyed.
I'm currently loving Chuck on Virgin 1, but I will not be buying a single DVD of it until I know it has reached a 'true' ending and not been cut off half way through.
If you can't give me the full story, I'm not giving you any money for it.