That makes sense. In particular, the minimum price is always wildly better because of the serverless model (metered, like S3), but you still want to see where you will be at with bursts and such, or compare to a static Postgres or DynamoDB cluster at expected load.

A lot of the benefit comes from not having to manage capacity up and down in the first place, though. Even if other systems let you do it quickly you still have to either predict or react to your load "by hand".