It is a huge step to go from monophonic to polyphonic pitch detection. Variaudio is strictly monophonic. If you look at the leader in doing polyphonic, Melodyne, you’ll find that their top end version costs about $150 more than Cubase Pro 10. Steinberg would presumably need to drop a huge amount in dev costs to even get in the same neighborhood as Melodyne. Also there’s an excellent chance that Celemony holds some patents that effectively block others from doing quality polyphonic detection.
The good news is that even the cheapest versions of Melodyne do amazing things.