I use Photopaint version 9 "by default" so am biassed.Also I feel that latest versions of Corel are web orientated or extra frills rather than huge improvements from the bottom.
A Photo Master Suite website says "includes Photopaint 11.......Photo editing".
I don't think it is a good idea. Paint Shop Pro which has a strong following in this forum is only 10% more, and Corel v. 11 from 300% to 600% more, presumably whether upgrade or outright full version.
On the basis of "owt for nowt" - Any bits of Photopaint v.11 you buy for that price will be lonely and not a lot of use compared with your v.9