First thing first, enable multi warehouse and locations.

Assign Full Acounting Features to responsible users.

Create Multi Warehouses.

In Product Category, Costing Method : Average and Inventory Valuation : Automated.

Create a product, make sure that is storable.

Warehouse wise costing tab inside the product. Here you find the warehouse wise cost of related products.

Purchase product at 10/units.

Make sure warehouse selection is correct in purchase order.

Receipt order Done.

As you can see the costing price added in warehouse wise cost tab in that product.

Now add some landed cost in purchased product.

As you can see the cost price are updated.

Now purchase same product with different price and different warehouse.

Different warehosue selection in purchase order.

Receipt order done

As you can see the another cost are added in costing table.

Now added another landed cost for last purchased product

As you can see the cost price is updated after adding landed cost.

Now make sale order for that product.

Warehouse selection in sale order.

Make invoice for that sale order and check the journal entries.

Journal entries after make delivery done.

Create another purchase order for same product but different price.

Warehouse selection in purchase order.

Incoming order successfuly done.

As you can see the cost price is update in products costing tab.

Check inventory valuation. Just select date and warehouse.

Valuation report for selected warehouse

Valuation report for another warehouse