12. Exemption and deduction.

(1) In determining the purchase price liable to tax, the amount relating to the purchases made within the local area from a registered dealer doing business in the same local area shall be deducted.

(2) All amounts received from the seller in respect of the goods returned to them by the dealer shall be deducted from the purchase price liable to tax provided that the goods were returned within a period of six months from the date of delivery of the goods.

(3) In determining the value of goods liable to tax, the value of goods purchased or received from outside the local area but subsequently sent out of the local area otherwise than by way of sale shall be deducted, provided that the goods are sent out of the local area within a period of six months from the date of entry of such goods into the local area and entries are made in the stock register in the manner specified in sub-rule (5) of rule 14.