Prime star, I don't think you'll get hit with that $5 fee. I seem to remember that last year, I jumped up to AT250 so that I could watch the NHL playoffs, some of which were on NBCSN, and as long as I kept that package level for at least a month, I wouldn't get hit with the $5 change fee.
Of course, this is all based on my sometimes shoddy memory!
As far as 200 vs 120, it is, of course based on personal preference, but for me, it's worth it. I like now having NBCSN, as well as NHL Net, MLB Net, NFL Net, Big 10, and of course, Nick Jr. and Disney XD for my little boy!!
Good luck with your choice!!