Reserved Instances lower costs by giving you the option to make a low, one-time payment to reserve compute capacity and receive a significant discount on the hourly charge for that instance. Reserved Instances are complementary to existing Red Hat Enterprise Linux On-Demand Instances and give you even more flexibility to reduce computing costs and gain access to a broad range of applications running upon a proven, dependable, and fully supported Linux distribution on the AWS Cloud.
If you want to use Reserved Instances with RHEL, you no longer need to perform additional steps to rebuild On-Demand RHEL AMIs before you can use them on Reserved Instances. Red Hat Enterprise Linux Reserved Instances are available in major versions both in 32-bit and 64-bit architectures, in all Regions except AWS GovCloud.
For technical information, check out the Getting Started Guide: Red Hat Enterprise Linux on Amazon EC2.
For pricing, consult the Amazon EC2 Running Red Hat Enterprise Linux page.
To make it even easier for you to get started, you can get a $50 AWS credit that you can use to launch EC2 instances running Red Hat Enterprise Linux.