2. Definitions

In this Act, unless the context otherwise requires,-

(26) "Purchase price" means the amount of valuable consideration paid or payable by a person for the purchase of any goods, less any sum allowed as cash discount according to ordinary trade practice, but including any sum charged for anything done by the seller in respect of the goods at the time of, or before, delivery thereof, other than the cost of freight or delivery or the cost of installation or interest when such cost or interest is separately charged ;