The agricultural land transfer tax is imposed on the consideration payable for the instrument of writing less: the total value of any improvements on the property; and the total value of any land not subject to the agricultural land transfer tax. If an instrument of writing transfers agricultural land with an improvement that has not been assessed by the supervisor, the grantor shall notify the supervisor at least 7 days before the date of transfer. For the purposes of paragraph (1) of this subsection, the supervisor shall: determine the estimated total value of the improvements on the most recent date of finality; and give the grantor at the time of the transfer a notice of the estimated value of the improvements. The grantor may appeal the estimated total value stated in the notice as provided by § 8-407 of this article.