Is it worth it to buy the game or the Fire and Ashes expansion?

Hi, I’m a huge fan of avatar. Have been since I watched the first film and later looked at the world of avatar and how they were made. I am really interested in playing the game but am jumping back and forth on if I should. Can anyone let me know why the game is worth buying or anything that makes it not worth buying? Also, for anyone who has bought the Fire and Ashes expansion, is that worth buying in on itself? Thank you!