Valuation of excisable goods for purposes of charging of duty of excise. (1) Where under this Act, the duty of excise is chargeable on any excisable goods with reference to value, such value shall, subject to the other provisions of this section be deemed to be (a) the normal price thereof, that is to say, the price at which such goods are ordinarily sold by the assessee to a buyer in the course of wholesale trade for delivery at the time and place of removal, where the buyer is not a related person and the price is the sole consideration for the sale: Provided that (i) where in accordance with the normal practice of the wholesale trade in such goods, such goods are sold 357 by the assessee at different prices to different classes of buyers (not being related persons) each such price, shall, subject to the existence of the other circumstances specified in clause (a), be deemed to be the normal price of such goods in relation to each such class of buyers; (ii) where such goods are sold by the assessee in the course of wholesale trade for delivery at the time and place of removal at a price fixed under any law for the time being in force, or at a price, being the maximum fixed under any such law, then, notwithstanding anything contained in cl.