At home in Canada I ride a 2008 GT200L and my wife rides a 2007 GTS250ie. I do all the maintenance. Zen and the Art of Vespa Maintenance. It's satisfying, relatively simple, small scale mechanics compared to a car or truck. These machines just go and go when properly maintained.
We recently returned from a month in Greece where we rented GTS 300s and adventured thousands of kms. The rental Vespas were terrific. For instance, on Corfu we rented two GTS 300's from Katerina & Nikos at Corfu Vespa Rentals and Tours where we completely took apart the entire island traversing the mountains over crazy switchbacks, finding hidden gem beaches to swim in the Ionian Sea in remote settings, and finding great tavernas, cafe's and bakeries. Highly recommend Corfu Vespa Rentals. Nikos does all the maintenance on their extensive Vespa fleet. One of our rentals there was a 2019 GTS 300 with 55,000 kms. From the way it looked and rode you'd think it was brand new. A testament to both Vespa's durability and to Nikos's meticulous, prideful care.
If the moto you're thinking of buying is sound, just maintain it well and don't worry about 30k miles.
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Viva Vespa!!