This depends on what AWS service we're talking about, doesn't it? For example a Kinesis stream compared to running a (say) 5 EC2 node Kafka cluster with zookeep

This depends on what AWS service we're talking about, doesn't it? For example a Kinesis stream compared to running a (say) 5 EC2 node Kafka cluster with zookeeper etc. Isn't it within the realm of possibility the managed service comes out cheaper?