I would guess the person selling it has no clue. This happens when estates are involved. The quilter passes and the family is left to liquidate all the sewing machines, etc. The people selling have absolutely no clue what they have or what they are selling and probably couldn't even tell you how to thread the machine. This could be a blessing or a curse. A blessing if they are letting the machine go for a fraction of its worth. A curse because they know nothing about the machine and couldn't help you with it if they wanted to, if something went wrong.
The good news is Nolting has a good reputation for customer support and will most likely support you with any issues even though you got the machine 2nd hand.
Nolting's beginner model, the fun quilter goes for $4,600 new with no frame and no stitch regulator.
http://www.funquilter.com/