Last week, someone emailed me to ask about a potential cost optimization mechanism in DynamoDB. More on the specifics of that situation below, but the basic point is they were thinking about adding some additional application and architectural complexity because they were concerned about high DynamoDB costs for a particular use case.
I responded the way I always respond for these requests -- "have you done the math?"
One of my favorite things about DynamoDB is that you can easily do the math when considering how much it will cost you. I use this all the time in a few different ways, from getting a rough guess at how much DynamoDB will cost for my application to deciding between different approaches to solving a specific access pattern.