Hey, @holger80:
Interesting that this would show that the posts/comments are more constant while the cost per vote is not. Mine is far from scientific, but the numbers I've pulled suggest exactly the opposite, and that it depends on where the comment is as to how much it actually costs in RCs.
Certainly not doubting your data. Just trying to reconcile it with what i think I'm seeing, which is more stabilization with vote costs and wild fluctuations in comment cost depending on comment level.