The 225 Opti has been around since 1997 (or there-abouts).
The first few model years had a significant number of "bugs" - typical with any new design.
By 2001/02 they pretty much had them ironed out after making some mechanical changes to the motors.
Cosmetically they look the same today as the first models out did.
I would personally want confirmation of the model year. If it's the original owner there should be paperwork etc (I hope it's been serviced at least a time or two).
If the motor is pre-2002 I would either pass on it or give it a pretty low value in calculating the value of the entire package.
The "discount" price of a brand new 225 Opti is about 16K - if this one is 5/6 years old I would expect it to be worth 1/2 the new price (with a tech check and documentation of service if it's a private deal - at least a 90 day warranty if from a dealer). If it's a 2002 thru 2007'ish model I would drop the value to maybe 5K. Older than that, if running well I would personally value it at no more than 2K as part of the entire package - but that's just my opinion....