Valuation of free samples under excise

Can any one clarify what is the appropriate basis of  valuation for free samples for charging excise duty...??

Would it be according to Rule 4 of Valuation Rules(value nearest to the time of Removal... which became the price available to wholesalers  by the factory in my problem)

or Rule 8(which says about Captive Consumption of goods i.e. 110% of cost of production according to the valuation rules).....