I had actually purchased the classes for Cost of Harshad Jaju sir for CA Inter. His concept of teaching the subject is really good. You will also get his classes in Pendrive as well as Google Drive mode depending on the type of preference you want. I actually benefitted from his classes because of his simple concepts and methodology in teaching the subject. Honestly speaking, his concepts easily place my preparations on board with mine. Do check him out!! I would suggest you could go opinion based as well!