The set of 30 figures doesn't include everything. There another fifteen or so that aren't included. Additionally, not all of the figures have bene released individually or in the small 5-pack, I know that Hagrid and Genny Weasley have not been released yet, except in that 30 pack.
Myself, I'm conflicted because Hagrid is a must-have for my layout, but I already have all of the available minis and that would make for quite a few duplicates. I'll have to see just how many. I guess I could always sell the excess, yeah?