Which $19.99 plan are you referring to? If you are asking about the student/teacher $19.99/mo offer that is going on right now, It is a full version of the creative suite and includes Muse, Edge and everything else that the Cloud subscription offers. The only caveat is you have to qualify as a student or teacher. If you do, it's an amazing deal.
Hope that helps
Michael Riordan
Adobe Certified Instructor
Digital DesignLab