Hello Noodles and welcome to the ArtRage forums
Unfortunately as Vitae is only available from the Apple and Microsoft App Stores there is no Upgrade discount now as there was in the past when sales of the older versions of AR were handled by Ambient Design themselves.
There are sales periodically throughout the year for Vitae, I think 3 so far this year, the most recent of which just finished on Monday.
If you are on Ambient’s mailing list, then you should get email notifications of sales when they happen.
But, if the rest of this year follows past sales patterns then the next should be around Halloween, possibly