Just see your dealer. No mention of price in the press release. My wild guess would be $8000. http://media.mclarenautomotive.com/en-gb/releases/514
...The McLaren Winter Wheels and Tyres set consists of four, 14-spoke Lightweight Forged wheels in Stealth finish, fitted with Pirelli MC Sottozero 3 winter tyres and incorporating the McLaren tyre pressure monitoring system. Developed by McLaren and Pirelli engineers specifically for the McLaren Sports Series family – the 540C, 570S, 570GT and new 570S Spider – the set comes fully assembled and ready to fit, allowing owners to swap quickly and easily to winter tyres and enjoy their McLaren to the full throughout the colder months… ...Pirelli MC Sottozero 3 tyres are branded with the ‘MC’ seal of approval and designed specifically for McLaren fitment to deliver optimal grip and control in adverse conditions. With a tread pattern that has a high drainage level reducing the chance of hydroplaning, the tyres provide maximum possible grip. They are effective on wet and dry roads when temperatures are low but not necessarily at freezing point; as a guide, once the ambient temperature regularly drops below 7 degrees Celsius (44 degrees Fahrenheit), both McLaren and Pirelli recommend the use of winter tyres….