I’d like to know what happens when item is updated? Are buyers allowed to re-download the new version free of charge?
An if so – is there any way to inform those buyers if the version have a major update (in my case – new features which are unique for that type of item).
Is it a good practice to let them know about this somehow?
1. Yes, they can download the new version. It basically gets replaced.
2. On your item description page, on Twitter, etc.
It’s good practice to keep your buyers up to date. It’s even better if you ask them to sign up to your “Envato-only mailing list” and send them updates there. But you’ll need, in this case, to state up-front exactly what they’re signing up for.