Cost of AWS MWAA

Good question!

So for MWAA, generally you'll pay for the environment since each Amazon MWAA environment includes the scheduler, web server, and 1 worker. That will be constantly running while MWAA is running and will be running after you create the environment. (Environment Class)

Then, if you need additional workers to scale up, this will be additional cost (but more burst capacity), as this will be variable.

Depending on how many schedulers, schedulers will be constantly running while you have the environment up. (Number of schedulers your environment will use).

Lastly you will be charged for database usage/storage - charged at a montly rate.

Thus, you'll pay for the environment and for additional workers as well.