hey.
The primary cost would be licenses per user that will be accessing the app (agents & Supervisors).
Omnichannel/CSW is based on Case Entity, so this means that each user (Agent) will require a Dynamics 365 Customer Service License, either Base (90USD per User/month). Besides this, there's the prerequisite of the "Customer Service Digital messaging Addon (75USD per user/month)" if you plan to use messaging, "Customer service Voice Channel AddIn (75USD per user/month)" if you plan to use Phone, or "customer Service Digital Messaging and Voice add in (90USD per user/Month)" if you plan to use both.
This means that each user would require at least Dynamics License (90US$) + an addOn that will be another 75US$ = 165US$ per agent/user an month.
Finally, if you plan to use Phone services, you'll need to purchase a number either from Azure Communication Services, or from the current provider you have.
If you are NOT interested in Omnichannel (messaging/Voice), then perhaps you can avoid using Customer Service Workspace and use the Customer Service Hub, which would only require the Dynamics 365 Customer Service License.
Regards,
