The basic Nectar Elements was included during the time of X3 as a freebie from XLN (log into your XLN account from Addictive Drums 2 to see if it is listed near the bottom in your account). Definitely redeem that so that you get customer pricing on upgrades. That version doesn't have a harmonizer though (unless I am completely forgetting something), but is still a fairly light-weight and very capable VST.
The follow-on Nectar 2 is what has the
harmonizing module, but it may also be extreme overkill for what the OP is doing (there are free/dirt cheap pitch shifters out there). That video shows a good big picture, but he doesn't even touch the "Pitch and Delay" tab (each harmony can have them different as well). BUT... basics can easily be done with a pitch shifter and "more tracks" in SONAR... the VST just has all the knobs and switches "in one place," as it were.
For iZotope (and most vendors), a registered product and a little patience leads to some wicked deals. iZotope's DDLY Dynamic Delay was another freebie given away a couple years ago. Also, iZotope has fully functional 10-day trials on most everything.