This was the source of my fustruation. I needed something quick and dirty to share with my clients. While I could create a spreadsheet to do it and there are a lot of them out there, I'd figure I just help others out there by creating a simple app.
Storage has been on my todo list. It's been a little difficult to grasph since AWS and Rackspace offer both block storage as well which charge differently than just straight GET/POST/PUT operations.
I feel your pain. I just attended a NoSQL conference this week and my head is spinning with the amount of service providers and solutions there exists. One day, I'd like to extend my calculator to include doing a full blown IaaS vs PaaS comparo.
To answer your question, getting a good handle of knowing your operation costs has happened after the fact your servers were spinning. Most of my clients assumed that going to Cloud will help you save money. That has not been the case and I had to keep calculating costs over and over again.
Have you thought about what the companies' problems are and how you can use Python to solve their problems? Yes, companies are looking for specific skills but there are companies that are looking for someone to fix their issues. They don't care how you implement it as much as it gets that issue off their backs.
So if you want to land a job or a client do some thinking on what their issues might be, their dreams, their goals, and maybe their fears. If you know these and can translate these into how you can implement solutions, then you will show them how much value you bring to the table. And when you can think of ways to create value, you can immediately charge almost anything.