Fair market value as actual cost: establishes FMV as the cost basis for business-used assets and clarifies derivatives tax rule. Where a specified capital asset is used for business or profession, the actual cost to the assessee shall be the fair market value previously taken into account for the relevant income provision. Additionally, for trading in agricultural commodity derivatives, the requirement that commodity transaction tax be chargeable under the commodity tax enactment shall not apply for the purposes of the specific proviso, clarifying application of that proviso to such derivative transactions.