I just wanted to pop back into this thread and add, that [as far as my question was concerned] I actually had two separate issues...
One was, I thought that my version (Ultra) that I purchased had gone on sale for less than 'my sale price that I paid at the time' - which it didn't - when I looked up the recent Sale Price, I was looking at a less-value-packed Edition (Deluxe). Which of course, costs less anyway
So, when I contacted CyberLink Support (via their website forms) I asked them about the Second question I had [thought of] - where I could possibly pay the difference between my version (Ultra) and the next one up (Ultimate), basically getting an 'upgrade' to the next Edition of PDR, paying the difference. Their friendly Support contacted me back and said that if I purchased the version I wanted (Ultimate) and sent them the Receipt for it, they would refund the price of the original purchase (Ultra) - so I would essentially have the 'upgrade' that I was looking for!
I'm sorry if this not something to normally be posted on the forums - I do not wish to overstep any rules - I just wanted to pop back in to point out the refreshingly helpful Support service that CyberLink seems to have!