(3) Subject to subsections (4) and (5), where subsection (1) or (2) applies in respect of a supply of goods or services subject to any fee, charge, or other amount, whether a fixed, maximum, or minimum fee, charge, or other amount, prescribed by, or determined under, any Act, regulation, or measure having force of law, that fee, charge, or other amount may be increased or must be decreased, as the case may be, by the amount of tax or additional tax chargeable, or the amount of tax no longer chargeable.