I'm pretty sure the materials are a minor fraction of what you're paying for, so I wouldn't expect such a huge difference between the price of bike and car tyres.
I'd say most of what you're paying for is the development of the design and the creation of the tooling; once that's amortised, a large fraction of the price would be profit. But that's a huge outlay to make up for, no doubt. I'm tipping the GP5000 will be unrelentingly pricey for at least two or three years...