I think it depends on the route you go for transcription. There are professional transcription companies that will do it or you could try and go a student route.The best thing to do if you do it on your own is to transcribe the interview after you've done it, as opposed to waiting until all your interviews are recorded (my mistake lol!)
I went professional when my hands began to have some horrible swelling/very painful, and I was having some nerve damage issues (which luckily, have since left!). It cost me about 2k (Australian mind you) for 20 1-2 hour interviews.
But I don't regret spending that money because it meant I could focus on my teaching commitments/allow my hands to heal, and as the transcripts came through, I could load them into my qualitative analysis software (I used Atlas.Ti which as a student you can get at a reduced rate).
If you don't mind spending the money, go professional. But you need to check and make sure your ethics allows for you to have your interviews transcribed by someone else, otherwise you can get in a heap of trouble.