Differences in Harry Potter

[flyfree432]

I am trying to decide which version to purchase of the Harry Potter release on blu-ray. I'm disposed to purchase the individual discs because it will be easier to add the last two movies when they are released, however amazon.com says that the 5 movie package contains "2-disc" versions of the film, then it says that there are a total of 7 discs. So I'm confused. I don't care about the bookmarks or trading cards, but do you lose all the special features in the individual packages? Thanks