4. Canberra Company's factory is operating at less than full capacity this year. It is currently purchasing parts from Australia used in its manufacturing operations. The purchase cost is $48 per unit (part) plus a 5% import tariff (tax) based on the sales price. Also, it costs $8 per unit for shipping. If Canberra makes the part in its own factory, the total cost per unit will be $62 including $4 per unit for fixed factory depreciation expense. 20,000 of the parts are normally purchased during the year. Now the parts can be manufactured by Canberra using unused capacity with no increase or decrease in fixed costs. Calculate the total increase or decrease in Canberra's net income from making the part rather than purchasing it