I'm assuming you are speaking about the autogiros built before World War II, prior to mass production of the helicopter. They were produced in very limited numbers, and few have survived to this day. While one example was sold and its restoration is nearing competition, I've not seen another one available for sale for many years. Look for this new Pitcairn restoration to be flying in the near future. We'll post photos of it as soon as they become available. The owner/restorers of this new restoration hope to have it here for AirVenture 2007.
Steve Pitcairn, the son of Harold Pitcairn, oversaw and participated in the restoration of a Pitcairn PCA-2 autogiro, which is now part of the collection of the EAA AirVenture Museum. It may fly one more time before it is permanently retired, but that is far from certain. Beyond those two, the only other ones I've seen are non-flying restorations or originals which are part of museum collections.
Editor, Vintage Airplane magazine
Executive Director, EAA's Vintage Aircraft Association