Penith Company manufactures stereos and can make or buy a particular subcomponent. The cost to manufacture the subcomponent is $4.00 for direct materials, $5.00 for direct labor, and $7.00 for variable overhead. If Penith buys the subcomponent, facilities that would be used to make the component can be rented to a tenant for $30,000 per month. If Penith requires 20,000 subcomponents per month, the maximum price per unit Penith should consider paying is