Clip Studio is basically the digitally distributed version of Manga Studio 5 which is normally physically distributed. At 100$ for the Pro(equivalent of Manga Studio 5 EX), it's a pretty nice deal for a software which costs normally about 300$.
Though I hear the only real thing EX has over Manga Studio 5 is more options for comic pages. So slightly less than 50$ for either Clip Studio(digitall distributed) or Manga Studio 5(physical distribution) is still a pretty neat deal since both versions are(afaik) still compatible with cutom brushes such as Ray Frenden's.