We store 100-1000 GB of data in each wide table on our untrendy on-prem SQL server boxes. 10GB is peanuts. In fact, I propose (given the limitations suggested by the author) that DynamoDB may have NO practical uses worth exploring. If NoSQL is about scale, and it can't scale, what's it good for?
I can understand having to optimize your key space, but in this case it necessitates extreme premature optimization.
You don't pay per node. In fact, the concept of a node is not exposed at all. Each shard is technically on three nodes for high availability. You pay for provisioned capacity and data storage per GB.
DynamoDB is a multi-tenant service. There is no dedicated node for you. Each shard is replicated across 3 nodes and those nodes contain replicas of other shards/tables.
I can understand having to optimize your key space, but in this case it necessitates extreme premature optimization.