See item 39: Purchases and other costs on the ATO website.
At label B, show the cost of direct materials used for manufacture, sale or exchange in deriving the gross proceeds or earnings of the business.
The amount at label B must reflect an amount calculated for tax purposes.
We've provided a generic schedule at this item for dissection and record keeping purposes.
CCH References
7-050 Small business entities
16-152 - Business expenses