You should simply buy it as "demo" means that you may try it for a limited time. Much noise is made here when some vendor finds his/her work being on another site by someone else. people lose their membership because they use some pixels that were created by someone else. Everyone here agrees this is the way to go. And you do the same. You use a demo long after it expired. So either buy it, or buy another app (or XP) that can do the same.

I have tried prudent planning long enough. From now I'll be mad. (Rumi)