Self-study can undermine confidence if he can't resist the urge to procrastinate "some more", and subsequent anxiety directly affects his IELTS band score. The time spent with an experienced tutor will definitely help you find the band you want whether it is IELTS Online Coaching or offline coaching. Confidence in your learning abilities may require the seriousness required of the exam, but you end up with a lower than required score and have to retake the exam, so you don't want to spend your IELTS money.