In my opinion, it depends on how much you think you'll get for each one.
If you think you could group them together and people would want them in a group, do that.
The reason I think this is better is because initiation fees and final value fees add up really quick.
On the other hand, if they are a variety of DVDs (martial arts, romance, workout videos, etc.), then I'd do them seperate.
Just my .02