I used to need a lot of transcriptions done for podcast type stuff and interviews. It's been awhile but this was a big help...
Introducing Typingpool, My Software for Easy Audio Transcription | Ryan Tate
Basically, if you cut MP3's/audio into 5-minute chunks, you can get them transcribed really cheap on Mturk. Again it's been awhile (a year or so) but I remember getting something like 1 hour of audio transcribed with 99%+ accuracy for around $20 total.
What that software does, you drop your recording into a folder, it automagically chops it up into 5-minute chunks, uploads it to an S3 bucket and posts the HITS (jobs) to MTURK, then as they come back it updates them to your screen so you can approve/disapprove from your desktop.
Once it's all done, you have a nice HTML file with your transcriptions all organized and ready to go.
Saved me a ton of time and money.
I had a linux VM setup on a Windows machine to handle it, it took about an hour to setup (I just followed instructions, I'm not real tech savvy) and after that it was great, literally just drop the file into a folder and let it run, approve it as it comes back and that's it.
Also, I was always wanting transcriptions in like an hour. If you're willing to wait a few days you can probably get them done for a lot less than $20 an hour.
Ymmv, but I found it a huge help.