Joint Upgrade Inc. produces premium hip implants. A component of each implant uses 1 hour on the machine that is the company's current constraint. If this component were bought from an outside source, the machine time that was used to make the component would be freed up to use on Joint Upgrade's knee replacement products that require 2 hours on the constraining machine. The knee replacement products have a contribution margin of $17.50 per unit. When deciding on whether to make or buy the component, what is the company's relevant per unit opportunity cost of continuing to make hip implants? Round your answer to the nearest cent