Here's what I know:
Most of the Nauticas around here are sold as tenders. I would say that they are mass produced and average to good quality. In the photo the boat looks sound but how long ago was the picture taken?
Assuming the tubes are in good shape, the hull in one piece and nothing striking falling off or apart, $3,900 isn't a bad price at all.
Proof however is in the pudding. Taking a look and taking a drive are two different "takes". $3,900 is not a good price if you've got a wounded 90hp jet drive. Let me just forward to guess that there is no such thing as liquid water in your area, in February
You could crank it to see what it sounds like but........