Under IAS 2, the cost of inventories must include all costs of purchase, costs of conversion, and other costs incurred in bringing the inventories to their present location and condition (IAS 2.10). This three-part framework is the foundation for every inventory costing decision your entity makes.
Costs of purchase are the first building block. These comprise the purchase price, import duties and other non-recoverable taxes, and transport, handling and other costs directly attributable to acquiring finished goods, materials and services. Trade discounts, rebates and similar items are deducted when arriving at the final figure (IAS 2.11).