Will Company assembles products from a group of interconnecting parts. The company produces some of the parts and buys some from outside vendors. The vendor for Part X has just increased its price by 35 percent, to $10 per unit for the first 5,000 units and $9 per additional unit ordered each year. The company uses 7, 500 units of Part X each year. Unit costs if the company makes the part are as follows. Direct materials Direct labor Variable overhead Variable selling costs for the assembled product Should Will Company continue to purchase Part X or begin making it