That is a compelling "buy" if the gun is indeed an early 59 NIB as you said.
It must be kept in mind the 59 is an historic gun - it was the first 'wonder nine' - a double/single action, double stack, alloy framed 9mm. It's historic. If this is an early one NIB it's worth more than that. S&W made H&K, Sig, and even Glock later, seem like late comers to the game with that gun. Granted, I have a polymer double stack 9mm that pre-dated the 59 by a few years, but it's a tetchy H&K VP70 with a puking 18lb DA trigger pull at each finger stroke. The S&W 59 was a dream gun to many when introduced. I'm neither a DA/SA fan, a 9mm fan, nor an alloy gun fan. But no serious modern hand-gunner who knows his stuff can NOT be a fan of the S&W 59.
The other posters have good points about 1st gen vs later S&W autos. But at the end of the day, if this gun is an early NIB 59 for that price, that's a no-brainer.