I'm looking for a breakdown of the common item, unique item and spell cards so I know what my chances are when buying certain cards. I've done a bit of googling and have not come up with anything.
Someone over on boardgame geek added a list of all cards for all expansions since I originally asked the question and did my search.
Board game geek has Elder Sign listed. One of files in the game listing should have the information that you're looking for. I'll point out that the game also has a number of expansion packs.