Cloud SQL can be thought of as a VM with MySQL (or PostgreSQL) installed on it, along with various associated services provided by the platform. So it ought to come as no surprise that the cost of a Cloud SQL instance can vary from $1,142/month to just $9/month. What's the big difference? It's all in the machine type we pick; the high bill refers to the custom machine type and the high-availability configuration (High Availability (HA)):
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