I've hear that Ducati is a motorcycle manufacter based in Bologna, Italy.
I've never heard of them. Have they been around for a long time?
it seems the company was founded in 1926 by Antonio Cavallieri Ducati and his three sons
Are these motorcycles sold in the united States?
Yes, they are.  The comany is now owned by German automotive manufacturer Audi and its Italian subsidiary Lamborghini.
Are they for on the road or are they used for racing, or both?
I am not sure, but I think probably for both.
I wonder how much one of these things costs. More than a Harley?
Harley-Davidson
Harley-Davidson, Inc., H-D, or Harley, is an American motorcycle manufacturer founded in 1903 in Milwaukee, Wisconsin. It was one of two major American motorcycle manufacturers to survive the Great Depression, along with Indian. The company has survived numerous ownership arrangements, subsidiary arrangements, periods of poor economic health and product quality, and intense global competition to become one of the world's largest motorcycle manufacturers and an iconic brand widely known for its loyal following. There are owner clubs and events
Ducati Motor Holding S.p.A.
Ducati Motor Holding S.p.A. is the motorcycle-manufacturing division of Italian company Ducati, headquartered in Bologna, Italy. The company is owned by German automotive manufacturer Audi through its Italian subsidiary Lamborghini, which is in turn owned by the Volkswagen Group.
History.
In 1926 Antonio Cavalieri Ducati and his three sons, Adriano, Marcello, and Bruno Cavalieri Ducati founded "Società Scientifica Radio Brevetti Ducati" in Bologna to produce vacuum tubes, condensers and other radio components. In 1935