If I stop an instance, I understand that I am not charged. However, I've installed several items on my machine in the last few hours (Mysql uploaded a db, Apache, PHP, etc...). I assume that when I stop the instance I retain these software installations, correct? Are these things stored in EBS? If so, where is the pricing listed for EBS, as I guess I will be charged every hour of every day for the whole year for my EBS storage given that it can never "stop"...
From http://aws.amazon.com/ec2/pricing/, the current rates are:
Your data will persist if the root device is EBS backed, which is default now. You can check in the EC2 control panel.
So stopping the instance (if 8GB EBS) will cost about $0.80 per month for storage if it is never running.