Google’s Speech to text service is not free! Yes, it offer 60 minutes per month for free. but when you transcribe more than 60 minute in a month. It charges $0.024 per minute, which is not a low price. I would like to recommand bluebee.cc.
It cost less money when you transcribe dozens of hours a month. Suppose you transcribe 1200 minutes (eg.20 hours) within a month.
Google: 0.024 * (1200–60) = $27.36
bluebee: $2.99
Google Speech to text service is almost 5 times expensive then bluebee! Year by year, it will save you a lot of money!