A company uses standard absorption costing to value inventory. Its fixed overhead absorption rate is GH12 per labour hour and each unit of production should take four hours. In a recent period where there was no opening inventory of finished goods, 20,000 units were produced using 100,000 labour hours. 18,000 units were sold. The actual profit was GH464,000. What profit would have been earned under a standard marginal costing system?