Hello,
I can do some transcription for you. I'm a native English speaker (from Canada) with a master's degree and professional transcription experience. I do a variety of freelance work, and I have transcribed research material, conferences, lectures, interviews, etc. Can show you some previous samples if you'd like to see, and I agree it's a good idea to do a trial project with one interview so you can see if you like my work.
I generally charge $1 per audio minute plus fees, assuming the audio is decent quality. (More for very poor recordings because they take longer.) Possibility of a discount for bulk work. I generally transcribe at a 4:1 rate, meaning it takes 4 minutes of work to complete 1 minute of recording, so if you want me to do a 30 minute test piece it would take me around 2 hours. I could do that today or tomorrow if you'd like to get started.
Let me know if you would like to discuss and I'd be pleased to work together on this.
Lasha