@josh,
Based the discription for the Basin plan

In AWS speak, this is an Auto Scaling Group that spins new instance based on a certain threshold.
So you have an instance with up to 8GB of RAM and can also get a second or third instance based on whatever criteria your ASG is configured.
Based on what you wrote, under that plan you can select different instance sizes, in the case xxxlarge will give you the 8GB memory?
My question is let say I picked xxlarge with auto scaling, why would it run of memory? Does the auto scaling group setting not set to see that if an instance is at 70% utilization spin a second instance?