If you're looking for PostgreSQL as a service, there's a few options out there...

• Database Labs at $19/mo on Digital Ocean, Amazon, and Google Cloud
• Amazon RDS works out to about $26/mo for a db.t2.micro instance
• ElephantSQL has a free option, then goes up to $19/mo, $99/mo, on up
• Aiven starts at $19/mo
• Compose starts at $17/mo
• Caspio starts free, and goes up to $59/mo, $249/mo and up