Is there a VST plugin I can get to correct pitch in vocal tracks, or another alternative without buying Melodyne etc, which are pretty costly. I am using Cubase Essential 4.
or upgrade Cubase…
What would be the best way to upgrade in order to get pitch correction?
Go to any shop and buy it…
What upgrade would be best to get
The one from your version to the full version (Cubase 7) if you want VariAudio and pitch correct plugin, or to Elements 6 or Artist 7 if you only want the pitch correct plugin.
Aloha M,
IMHO If you want gimmicks, chipmunks, Darth Vader, yes
If you want what sounds like real human voxes, no
Melo and Auto-T are the best things available to date.
I use them both and still I find many many limitations.
Which means in a way Vari is not that bad when you consider
it comes free with Cubase. 
I see Melo and Auto as my big brothers and Vari as my lil sister.
They are all in the same family but Vari, while being useful at times,
just does not have the ‘muscle’ of the other two.
In the DAW world when it comes to pitch correction, it is true
‘you get what you pay for’.
HTH (hope this helps)
{‘-’}
^ ^ ^ ^ ^ Best answer!