Okay its not a vespa but I've seen a few of the original petrol driven ones in my time. Quite a fascinating concept, upgrade the motor depending on your ability and laws about young driver, buy your 50cc when 16 then pop in a motor upgrade when able to drive bike with more power, https://cezeta.com/type506
The whopping £11500 custom motor in thr 506/02 got nearly 15bhp and top speed 71mph but should imagine extremely quickly.