The pricing depends on production costs. Unsure, what that exactly entails. If they need, to hire more people for these leagues or not. Also not sure, if SI pays to have these extra leagues in it... and all of this, among other things, affects final pricing. I think that FM is currently becoming a bit expensive.
I was under the impression that researchers were on a volunteer basis...
I also was under the impression, that the leagues were added based on what kind of research the team had on those respected teams, and not a licensing thing (since we are not allowed to discuss it, for some reason).
Anyway, yes, I think is debatable. Yes, fans do an excellent job in their spare time, glad there is an editor for it. They do this for the love of the game and these leagues. I think the death of Classic mode, was simply that, lack of an editor. You can question my reasoning for this. And yes, I think Si should be the one adding these leagues or have a more flexible editor, for example, the ability to add extra nations (existing ones or fantasy).