I downloaded it (it's an amazing piece of software btw) and checked what he put in the "about" box: It's still GPL, thank god. As far as I know, this doesn't force him to actively distribute the sources with the binary or make them available for download. He just mustn't refuse to send you the code if you ask for it.

Again, though: It's really great. Stunningly beautiful, a lot of options to customize your it, easy to use.... You'll never want to look at the real sky again.

I think € 3,00 is a very fair price for this quality (given I paid € 0,90 for a lousy jpeg image today) and I hope Fabien sees a fair amount of downloads through the store, even if people could get it for free legally. That would be encouraging for those who don't want to give up open development, but don't mind earning a few cents if possible.