These are getting to be a pretty old tyre design - hence the price, but well rated by some - these were used by the CSS for a while and the r6 cup boys used these before the 208RR came out.
Do they still make these? There must be some in stock at the places selling them cheap, but do they have a shelf life? Can you tell how old tyres are from some serial codes on the tyres or similar?
Also, what are you looking to use them for? Road / Track combination?