I bought a used 2002 Cambio Coupe sight unseen from a Maserati dealer in Minneapolis (I live in Chicago) and I have been very happy. Just a few things I would ask about that might affect the price you are willing to pay but no "gotchas". Most of the stuff I would have asked about are things I would have wanted the dealer to fix up before I got the car.
Get the clutch checked out. If you trust the dealer, they should be able to tell you how much is left. Esp. important if it is a cambio. My clutch was already near death when I got it - luckily the dealer here in Chicago replaced it under warranty but your mileage may vary on that one and clutches are not cheap but then again, you can always buy a new one and probably will have to eventually.
It would be nice to confirm that it is still under warranty - a Carfax report should be able to tell you this. My car had 4 minor problems that the dealer fixed under warranty.
Ask your dealer to throw in a set of snow tires - you will need them in even the most mild of winter storms trust me. I grew up in Michigan with only rwd cars, so I thought I did not need winter tires given the nice weight distribution the car has. But the stock tires are just too soft and lack any cutting tread and the car will just skate back, left, right whatever without snow tires.
If you like to listen to CDs while you drive, hopefully you will be buying one of the models with a CD changer - if not, you may be out of luck without spending a lot more money. The single slot CD player in the driver compartment sucks and there is no wiring in most 2002 models for a changer to be added - plus, most car stereo shops will not TOUCH the Maserati (and for good reason, the stereo is integrated with the computer wiring and you can actually mess up the engine or suspension). If the car you are looking at does not have a CD changer, ask the dealer whether it is one of the later 2002 models that at least has the CD changer harness already in, or ask the dealer if they would install a harness (about 5-7 hours of labor).
Of course if you can drive the car, drive it as much as possible. If it is a cambio, watch out for unusual hestitation or vibration on shifting (indicates a clutch problem most likely) since you cannot otherwise "feel" the clutch pedal.
You might also want to see if you can get a good deal on the Tubi exhaust setup as part of the sale - the stock exhaust is very restrictive (quiet) and major performance gains are possible just with the Tubi.
Finally, make sure you check pricing all over and especially online (ebay and duPont registry). I found that local dealer asking prices were about $20,000 more than actual selling prices. I am sure most of the prices are very negotiable - especially if instead of cash discounts you ask for a bunch of upgrades.