I'm 27.
When I worked at a Ducati dealer, it was typically the young professional or successful..er...gentlemen *ahem*...that were most likely to buy a Ducati. It's a premium brand, with a premium price, so they typically require a more financially established individual. We always had the droolers and the guys that would say 'I don't see why Ducatis are worth so much'...those weren't buyers and usually, either because of age or financial situation...or both.
I would say an average age for a superbike buyer would be around 30-32....of course you will have outliers. We sold an 1198 to a guy that was 60something and 848s to military guys with money to burn at age 20.