RC- The price will vary depending on the size and type of vehicle. The only ones I have any experience with are the Goodyears that came on my boss' C-5 Corvette, and they were about $290/corner (@NTW), and will allow you to 'limp home' at up to 55 mph. I've also seen a video demonstration of Pirelli's run-flat offering where they drilled a 1" hole in the sidewall and then went out on the test track. The test car was an Audi A-4, the car seemed to drive normally, and the test driver commented that the handling was quite neutral and the loss of pressure was barely noticable (not a good thing in my mind-), but speeds were limited to 100 kph (62 mph). FWIW, they are used on the presidential limo and SS chase vehicles (don't know the brand), and are part of BMW's "Protective" package (Pirellis or Michelin). HTH, M2