On 1 July 2019, Marble Ltd purchased a machine at a cost of $220,000 (GST inclusive) for use in its business. Marble determined the machine to have an effective life of five years and claimed diminishing value depreciation on that basis. Marble used the machine only for business purposes and sold it for $99,000 (GST inclusive) on 30 June 2023.

Required: Advise Marble on the taxation implications of these transactions.