You could buy used from a dealers and get a warranty maybe, prob only be 3-6mth tho.
You may lose more on a new bike when you come to sell it, depends on the milage you put on it etc.
Also bear in mind if you buy new then derestrict it then it may affect your warranty, so ask 1st if you do buy new.
If I could have afforded it I would have got a brand new scoot but im using mine daily for work so get the use from it, making it worth while.
If you want hassle free with no worries, and can afford it, then I would buy new. If your on a budget or want to upgrade it, derestrict it etc then buy 2nd hand.