I sold it because I wasn't using it anymore and I thought I could just as well do someone else a favor with it. Since it's only €30 (which isn't much for such a great plugin), I wasn't going to make a fortune out of selling it.
Using pirated software is a bad idea. In the long run, it means developers have less resources for developing new products, which is beneficial for none.
If anyone is interested in Dune 2, let me know!