Used
SeaDoo's historically take a real nose dive the first three years, and you are going to be upside down on the loan real quick.
If it were me I would (and did) buy a SeaDoo that I could afford, even if you have to speed a few hundred dollars on repairs, you're much better off than buying new.
SeaDoo's are very simple machines and most repairs and upkeep you can do yourself, at least on a 2 stroke ski.
Lou