A Pricebook is the standard Salesforce version of a price list, or container of products and pricing. In CPQ, we use the Price List object as the pricing container. Standard Salesforce synchronization requires that a Salesforce Pricebook is assigned to the Opportunity to enable synchronization between Quote and Opportunity. The Pricebook may be assigned to the Opportunity manually or automatically using a trigger. In either case, the Standard Price Book should be used.
To assign a default pricebook
You must have an existing Quote/Proposal created from an Opportunity.
Go to the Opportunities tab and select an existing opportunity.
Scroll down to the Products related list, and click Choose Price Book.
From the Price Book picklist, select Standard Price Book.
Click Save.
A standard price book is assigned to the opportunity. Go to the Quote/Proposal and make it Primary.