Davis Company currently buys a component part for $6.60 per unit. Davis estimates that making the part would require $5.10 per unit of direct materials and $2.60 per unit of direct labor. Davis normally applies overhead using a predetermined overhead rate of 125% of direct labor cost. Davis estimates incremental overhead of $2.10 per unit to make the part. The net incremental cost or savings of making the component is: Multiple Choice $3.20 savings per unit. $4.20 savings per unit $1.30 cost per unit. $4.20 cost per unit. $3.20 cost per unit.