I have a couple of 444N models;- one of the earlier ones with the medallion on the upper joint and another with the medallion on the bell;- both are the more standard keywork. I have noticed that these "brass" medallions are curiously resistant to tarnish- I am not quite sure that those medallions are brass. Raw brass turns very dark brown in a short period of time and the medallions are not lacquered. All of those medallions that I have seen are still fairly bright yellow. One of the medallions on mine has considerable surface wear and there is no indication that it is a plated metal.
I am not in agreement that the instrument is too complicated for a beginner. It might be more valuable than something you want to send to school with a junior high schooler though. The additional key(s) could easily be ignored by a beginner. All I see is the full Boehm extra right hand pinkie key, which is probably pretty handy. I can't see the upper joint rings in the photos, but if it is a 7 ring model, the additional ring in the upper joint is something one does not even notice except that it is highly advantageous when one gets around to playing E major scales and arpeggios. My first thought is that if your son is learning clarinet, save it for him when he is ready for an upgrade and get him a decent beginner instrument in between. If he gives it up before needing a better clarinet, then sell it.
I would definitely say that if the instrument is in good shape and has no cracks, past damage, no defects in the keys or wood that $500 is probably the bottom price and it might go for considerably more at an auction. That is a rare professional model Conn and the 444N cousin is a highly sought after instrument that has excellent intonation and is, IMO, a better professional clarinet that a host of later more contemporary models. Most people that would be working at a music store now are just too young to realize what you have there. Old clarinerds like me;- my mouth waters.....
