Send a message to all users (like a broadcast)

ChrisHoardMVP Is the Company Communicator free? I noticed it is asking for App Service and Service Bus subscriptions, paid services on top of our Office 365 subscription (E5) or pay-as-you-go. 

Does it cost to send each broadcast message? 

I like the use cases, but the complex setup process puts me off. 

I proposed this to the team, but they were wondering if everyone can have permission to post, with a select few having to approve the message before the message gets sent to all users.

For example - The lift is not working; Organisational survey; Team announcements;