AWS Billing

https://blog.cloudability.com/what-you-need-to-know-about-blended-rates-on-aws/
https://support.cloudability.com/hc/en-us/articles/206972637-Vlog-How-to-calculate-AWS-blended-and-unblended-rates
https://www.cloudhealthtech.com/blog/breaking-down-blended-costs-aws-ec2-reserved-instances
http://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/con-bill-blended-rates.html
http://awsdocs.s3.amazonaws.com/awsaccountbilling/latest/awsaccountbilling-about.pdf