(d) Leigheas Devices Company Limited sells product A at a selling price of $40 per unit. It's cost per unit based on the full capacity of 500,000 units is as follows: Direct Materials $6 Direct Labour $3 Indirect Manufacturing (60% of which is fixed) $10 $19 A one-time-only special order offering to buy 50,000 units was received from an overseas distributor. The only other costs that would be incurred on this order would be $4 per unit for shipping. Leigheas Devices Company Limited has sufficient existing capacity to manufacture the additional units. In negotiating a price for the special order, it's Sales Director wishes to know what the minimum selling price per unit should be. You are required to calculate the minimum selling price per unit for her.