(ii) Gross value. Gross value is the price at which the property would change hands between an unrelated willing buyer and willing seller, neither being under any compulsion to buy or to sell and both having reasonable knowledge of all relevant facts. Generally, with respect to trade or business assets, going concern value should be used as it will provide the most accurate reflection of such a price. However, taxpayers may use other methods of valuation if they can establish that such method will provide a more accurate determination of gross value and if they consistently apply such method to all assets to be valued. See subdivisions (3) and (4) of this paragraph (o) for special rules with respect to the valuation of leases and of intangible assets.