I'm going to provide some service for media content management. I will use Ec2 instances for service hosting. So, what are reasonable margins to Ec2 prices? What guides exist for such a matter? I want to avoid a situation when somebody will borrow my idea and cut me off simply by lower prices. Let's think for simplicity that competitor will also use Ec2.
Even rough estimations such as 10%, 40%, 200% would be fine.
Mnn, respectfully, I think you're looking at this from the wrong perspective. Don't price based on what your manufacturing cost is; price on what the value is for your end customer.
So the fact that you're hosted on EC2 is immaterial to your pricing. You can, if you want to, explain this in an FAQ somewhere, only to provide some reassurance that you're professionally hosted and scalable.
The question is what pain does your "service for media content management" solve, and what is the solution worth to your customers.