E-Bay has one for sale that is advertised as "rare". $400.00. I thought they all were all rare to be honest. They showed a picture of the backside of it with the power cord. It doesn't have a ground prong. Cut into it and you'll probably find the cloth they used to use to insulate the wiring.
They make a good conversation piece.
Yup, I'm pretty sure at this point they're all "rare." It would be a great conversation piece. $400 is a little steep for a conversation piece though. Is this the one that you found? It's for cheaper than you mentioned, but it might not have sold last time. I don't know how well wire recorders sell.