In accordance with Article 5(1), the customs value shall be established on the basis of the price at which the goods are sold in the state in which they were imported to an independent buyer in the country of importation. The importer shall also have the right to have products processed after importation assessed in accordance with Article 5, if the importer so requests. In accordance with Article 6, the customs value shall be calculated on the basis of the calculated value. These two methods pose certain difficulties and, in this context, the importer has the right, in accordance with Article 4, to choose the order of application of the two methods. Upon written request, the importer shall have the right to declare in writing by the customs administration of the importing country how the customs value of the goods for customs purposes has been established. Under the Agreement, the customs authorities may add to the transaction value of something only the following additions: 3. .