Hi Folcon,
Glad that the talk helped. The pricing page page has some information and links out to the AWS calculators, and this forum thread has more information about production. Note that with ions you should also model the AWS Lambda and API Gateway costs (if you are using these optional features).
That said, it is easy and inexpensive to start a system (e.g. just for a few hours) and try a representative load for your actual domain. I strongly recommend that anyone building any cloud app do this. We would love to hear about your experience doing this.