If you are an Amazon seller, open Analytics and select the Inventory valuation tab. Under the title, select Valuation history. (It is also in the sidebar under Analytics.) This lets you view snapshots of your inventory valuation over time.
For each month, a card shows the value, the units, the SKUs, and the countries. You can:
Select Review to see the details for the month: total value, units, SKUs, countries, and Line details for each SKU.
Select Export CSV to export the details.
Select Rebuild with current costs to replace the saved valuation with amounts calculated from your current Default costs. This does not post to your accounting software.
The first report appears after your first full month of Amazon inventory data. It uses your Default costs.