Melodyne base version comes free with sonar. I was never nagged to upgrade, only register it.
I used V-vocal loyally in earlier versions of Sonar (X1+X2) but once I tried out Melodyne I could not ever reasonably think about going back to V-vocal. There is a learning curve of course, like anything else but it does simple auto tuning, auto snapping, pitch correction tasks 2 times as fast as V-vocal ever did. Not only that but you can enlarge the Melodyne interface to see a much larger diagram of notes your working on.