There are different methods to pull out inventory information let it be quantity or costs. Take a look at the following modules under inventory reports:
1. Inventory Audit Report - Gives you price balances of items
2. Inventory Posting List - Gives you detailed breakdown of inventory transactions i.e. Goods Receipt, Goods Issue, Goods Return, etc
3. Inventory Status - Gives you the current inventory picture, quantity wise based on the selection criteria
4. Inventory In Warehouse Report - Gives you the current inventory picture, quantity wise based on the selected Warehouse
You can pull the above reports in SAP from Modules > Inventory > Inventory Reports
Learn more on Inventory Reports from the following resource:
Open a ticket with Support if you have a custom report requirement: