It goes to 257 mph... and the reason why it doesn't go beyond that is the Gov't decided that anything beyond that is deemed 'unsafe', both for the car and the rated tires. The Veryon has a governor that limits it to 257. It theoretically can go faster.
The tires do NOT need to be replaced every year. Unless you're doing 10,000 miles a year and driving it hard. And NO the tires do not cost $26,000. The real problem is that if you lose a tire it might be a while before you can get a new one.