(1) There are 2 methods for working out the notional wholesale selling price for a * taxable dealing that is either:
(a) a * retail sale of * grape wine; or
(b) an * AOU connected with retail sales of wine that is grape wine.
(2) The * half retail price method is used unless you have chosen under subsection ( 3) to use the * average wholesale price method.
(3) You may choose to use the * average wholesale price method if, during the * tax period in respect of which you are liable to pay wine tax on the dealing, at least 10% by value of all your sales of * grape wine that:
(a) is of the same vintage as the grape wine to which the dealing relates; and
(b) is produced from the same grape varieties, or the same blend of grape varieties, as the grape wine to which the dealing relates;
are * wholesale sales.