I've recommended the software to my consultant wife (since her company would be paying), but I'm cheap.

How does the pricing work if I want to do revisions to a document? Say it goes through a lot of editing, does each export count towards the maximum number allowed?

If not, what's to prevent users from doing entirely new documents under the guise of "edits" to an old document?

I think you're exaggerating the difficulty of your competition. :)