Q:

Standalone CPQ Licensing?

In reviewing the CPQ Pricing Page, I am wondering whether these licenses need to be purchased in addition to Sales Cloud and/or Community Cloud licenses.
I have a scenario where an AppExchange solution is creating Leads and Opportunities for external users via an API level integration. There is a request to enable CPQ functionality in the Salesforce UI to these external users and I am trying to figure out the minimum licensing required to do this.
These users only need access to the CPQ objects, but it seems like we would be required to provision them full Sales Cloud and/or Community Cloud licenses. Is this correct? Or is it possible to enable CPQ functionality only, with no access to other CRM objects such as Lead/Opportunity/Case, etc?

A:

Salesforce CPQ functionality uses following data model.

So, the licensing should be considered where you have access to Standard CRM objects, as well as access to Custom objects.
To access Opportunity, you should have Partner Community license for external users.

Finally, refer Salesforce Quote-to-Cash Pricing.
Where 

CPQ license cost is $75/month/user (billed annually) - 

Configure, Price, Quote (CPQ) with renewal and order automation

CPQ+ license cost is $150/month/user (billed annually)

Deeply customisable CPQ for your business.

CPQ+ with Billing - Custom Pricing.

Connect Quotes, Contracts, Orders and Invoices on a Single Platform

