Unless the supplies are entitled to duty-free treatment under a special category in the Harmonized Tariff Schedule of the United States (e.g., the Caribbean Basin Economic Recovery Act or a Free Trade Agreement), or unless the supplies already have entered into the customs territory of the United States and the contractor already has paid the duty, DoD will issue duty-free entry certificates for—

(1) Qualifying country supplies (end products and components);

(2) Eligible products (end products but not components) under contracts covered by the World Trade Organization Government Procurement Agreement or a Free Trade Agreement; and

(3) Other foreign supplies for which the contractor estimates that duty will exceed $300 per shipment into the customs territory of the United States.