I moved up from a 150cc scooter to a motorcycle last summer. I skipped a few steps and bought a Ducati GT1000. It is not a jump that I’d endorse for everyone, though it has worked out for me so far. If you are going to keep your Vespa, much as I’ve kept my Buddy-it is incredibly practical for errands in town, I’d strongly recommend moving up in size. Just too much overlap in what a 250cc scooter and 250cc motorcycle are capable of. People seem to love the SV650 and that would be a nice step up from the Vespa. However if you really want a Thruxton, Bonnie or Sportster I think you owe it to yourself to consider them, it’s not as if you’re lusting after a ‘Busa(the official BBM poster child of bad motorcycle choices).