I think that most of the "pirates" would never buy your software. It's in my opinion a misconception to think that the users would buy the product if they could

I think that most of the "pirates" would never buy your software. It's in my opinion a misconception to think that the users would buy the product if they couldn't work with the non licensed copy. The reason for that can be multifaceted. Some a lazy to search for free alternatives, others have no money or the software isn't worthy enough for them. I wouldn't try to convince them or putting many efforts into preventing copying. I would of course do some hints into the software to show them where to buy the full package. See it as the not beloved but some way effective marketing ;)