Couchbase is priced per node regardless of concurrent feature use per node. Appropriate sizing, eventually, may revolve around specific feature needs as you scale.
Does this help? Also there is a sizing guide on https://www.couchbase.com
Couchbase is currently a software package with many licensing and support options. If you have an enterprise size need then you would likely fall in the cost based category and there is a cost associated with production licensing.
If you are developing apps and need to use something document based, cross platform and cross-cloud, the. It is free to use, until you go into a stage/prod environment.
If you’d like to know more about cost I’d like to suggest a basic sizing and application requirements discussion.
You can reach us at https://www.couchbase.com or email and a technical representative will be happy to discuss options!
Does this make sense?