Hi, and welcome!
I know each market's different, but here in the SoCal neighborhoods I visit, I could probably get $50-$75 more for my blue MK512 than the $260 or so it cost eight or nine years ago w/o any discussion. And that's "used" price.
So, to me, Contender's mention of NIB around $350 sounds like a bargain, and I probably wouldn't flinch at $375. But that's judging by OUR prices: be sure to do your homework! Seems a bargain always pops up if you're patient.
Rick C