As it's just the gun and the one mag $550. is a fair price on the low end. It actually makes a difference that you're in KCMO. Other parts of the country a fair price would be $600. to $650. for the same gun.
Like Walt says the gun is in good to very good condition. Should be a great shooter. It may even become your favorite 9mm.
Drop by here when you have time for a few ideas...
http://hipowersandhandguns.com/
tipoc