10 Parts and equipment installed on the tax exempt goods mentioned in sections 1, 2, 4, 5, 6, 7 and 9 of this Part or designed for permanent installation on the tax exempt goods mentioned in section 3 of this Part where the sale price by the Canadian manufacturer or the duty paid value of the imported article exceeds two thousand dollars per unit; all parts and equipment installed on the tax exempt goods mentioned in sections 1, 2, 3, 4, 5, 6, 7 and 9 of this Part prior to the first use of those tax exempt goods; except that parts and equipment installed on the tax exempt goods mentioned in section 1 of this Part are exempted from tax only if they are designed to facilitate the carriage or handling of freight.