There's no fair way to calculate the cost. Ferrari themselves probably don't know what it costs. The cost of materials and labor is pretty straightforward, but a wing represents hundreds of person-hours of development time. There are many hours spent in a wind tunnel- how do you account for that? CFD time, etc. Ferrari has huge fixed overhead costs with a fancy factory and lots of cling-ons. How do you divvy those costs up at the component level? If they were selling wings to customer teams, all those fixed costs would matter. But they're not, so they don't. It costs what it costs.