For the purposes of imposing supplementary duty, the value of supplementary duty imposable goods and services shall be as follows, namely:–

(a) in relation to imported goods subject to supplementary duty, the very value that is arrived at adding customs duty, ¹[regulatory duty and other duties] (if any) with the customs duty imposable value under section 25 or 25(a) of ²[the Customs Act];

(b) in relation to supply of goods or services subject to supplementary duty, the value of such taxable supply shall be arrived at by deducting the supplementary duty from the value determined under section 32:

       Provided that if the supply of any goods or service subject to supplementary duty is made without any consideration or with inadequate consideration‚ the value for imposition of supplementary duty on such goods or service shall be arrived at by deducting supplementary duty from the tax fraction deducted fair market price of such supply; and

(c) in relation to any goods where VAT is imposed on the basis of ³[maximum retail prices], the ⁴[maximum retail price] described in section 58(2) shall be regarded as the value for imposition of supplementary duty.