The short answer to your question is to buy new if you can afford it. You'll get piece of mind that goes along with a warranty and theft insurance (only offered on new scoots to the original purchaser for the first 2 years if I recall correctly). Buying 2nd hand means no theft insurance.
Although that's fairly high mileage for a used scoot that new there in Taiwan, reliability should be no problem as long as it remained stock. If it looks tricked-out, or modded, don't even make an offer - keep looking.
The long answer is that the 2nd-hand asking prices tend to be inflated quite a bit in Taiwan, and if you have good bargaining skills you should be able to get the price down on a used scoot by a good amount. Keep in mind you can also negotiate with dealers for a more decent out-the-door price and/or accessories/services than what Kymco lists.
Also, depending on how long you intend to live there, this is what I'd do if I knew I'd be there more than a year:
First buy fairly recent 125cc or 150cc scoot. It more than enough to get you around town. Heck, I just did an "around the island" trip on my SYM Fighter 150 while there last month. Or buy a 250cc DINK (249cc, so still legal for you to buy) or such if you really want more power - being an older design, they'll be much cheaper than the Nikita's.
After 1 year, go take the safety class, get your "Heavy motorcycle" license, and then grab the 300cc Nikita. That way you'll be able to enjoy the benefits of access to the expressways if necessary.
Incidently, which city are you at in Taiwan?
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