Dear Akram,
Are you from Purchase Department? Cost of the material is nothing but the cost charged by the supplier. However, to acquire the material, you incur other costs too. These are (a) Transportation (b) Taxes (c) Insurance (d) Freight Forwarder charges, if applicable (e) Import duty, if applicable (f) Labour handling charges at each place where loading and offloading takes place (g) Cost of inspection of the material.
Thanks,
Dinesh Divekar