So here is the question. If someone buys Extended license for PSD file on Themeforest and creates lets say WordPress theme from this PSD , can you then sell this theme here?
No, you’re not allowed to sell items on Themeforest which use other peoples work
Edit: See you answered it while typing!
Well, read reviewers and envato staff comments on it and it looks like : 1.You can do so if you have PSD authors permission and you are maybe sharing profit; 2. You can do so if you sell that item on other marketplace; 3. You can do so if you have PSD template (with appropriate license and permission) from other place.
Am I right?
The first option makes the most sense i.e to share profit with the author but you still need author’s permission. Even if you are selling it on a different marketplace, the author still deserves his cut for all his hard work.