Not only that but they have to be filled with Nitrogen . Apparently, insurance is invalidated if you run standard ie non run flats and a set of tyres is around £1,500. Just running through some of the figures on the GTR forums I'm guessing you're looking at 3-5x the running cost of a 350/370, everything seems to cost a mind boggling fortune. If I'm reading this properly, you need a service every 6k at £680 and Disks and brakes every 12k at a mouth watering £1,700. The big service has to be done at 24k. On the plus side, insurance is not that much higher than a 350/370.
Pete
Most tyre places now offer nitrogen, I have mine filled with the stuff... something to do with bigger molecules so less escapes and they are not affected by temperature when compared to air. I paid £2 per wheel