I've always saved all of my passes from various conventions (C2, Comic Con, Wizard World, etc.), but obviously the C2 pass is the SW specific one, which makes it much more cool than the others. As much as I'd like to get a complete set of them, it's just not as high on my list of collecting priorities as some other items currently are.
But Matt, I seem to recall the Fan Club site offering the badges in sets at some point - probably after the convention's conclusion, I'd guess. I want to say the full set was around $60. Hopefully someone who has a better memory bank than my senile ol' noggin does can chime in with some more accurate info though.
But seeing as they're making multiple passes for C3, and they seem to be aware of the intrensic collectibility of said passes, I wouldn't be surprised to see them offer up another set of them later on, like next month. Of course, if you're actually going to C3, there's another way you could potentially get your hands on some... Ask folks at the convention if you can have their passes at the end of the day when they're leaving, if they don't want to keep them. I know some folks have tried that before, to some avail.
Heck, maybe some of the JD folks here have no desire to keep theirs afterwards, and wouldn't mind hooking you up with theirs...
Good luck with 'em Matt!