Kirkland Company manufactures a part for use in its production of hats. When 10,000 items are produced, the costs per unit are:

Direct materials $0.60

Direct manufacturing labor 3.00

Variable manufacturing overhead 1.20

Fixed manufacturing overhead 1.60

Total $6.40

Mike Company has offered to sell to Kirkland Company 10,000 units of the part for $6.00 per unit. The plant facilities could be used to manufacture another item at a savings of $9,000 if Kirkland accepts the offer. In addition, $1.00 per unit of fixed manufacturing overhead on the original item would be eliminated. (HINT: $.60 will NOT differ between these two alternatives.)

What is the relevant per unit cost for the original part?