John Martins is a department store in Adelaide. Its menswear department stock of suits, ties, and shirts at the beginning of the income year was valued at $1.1m (Including GST) and they purchased further supplies for $2.2m (Including GST) during the year. Its stock at the end of the income year was valued at $550,000 (Including GST) and its sales revenue for the year was $11m (Including GST).

How will John Martins treat its trading stock for income tax purposes, what amounts will be included as income, and what amounts will be allowed as a deduction?