Marketing? A particularly poor example

Sometimes you have to wonder at what goes through the heads of the marketing boys. In the shop today I saw the four disc edition of Hellboy 1 and 2. Now I happen to think they are both very good movies, even if the second one does veer a bit too much towards "Neverending Story". I have already bought the two disc edition of the first film but the price was low enough to tempt me to buy the full package, just a couple of quid dearer than the second movie alone. So, I picked up the box from the shelf to find out what extras were included.
To my astonishment the only information on the box was that both Hellboy and Hellboy II were "included". Nothing else. Not a single item of information. And it was sealed so it couldn't be opened to check the inside details. I'm guessing that it contains exactly the same extras as the two individual purchases would but I don't know that for sure. What's the point of producing a four disc package but not telling anyone what's in it?
My search of the internet to get the information has also been a failure beyond finding quite a few other people making the same complaint.
I've decided to save a couple of quid and buy the Hellboy II disc on its own. The marketing strategy seems to be to actively discourage purchase of the more expensive version. How very odd.