CFAI online exam

Is it worth taking? I just finished my book 6 3 am and 3 pm got 70.8% in 3 am got 71.6% in 3 pm Still a little nervous. Ethics is a wild card for me. If I do well, I could get more than 80% right, but sometimes I can miss 50%. Econ is definitely a weak part for me. I never score over 70%. To be honest, I hate econ since the first day in school. So, I am planning the last week now. I should focus on the notes for those concepts that I may neglect or just those problems I did wrong in book 6? The online exam is way too expensive, should I take it ? Any difference to Book6 exams?