I just got one of these and it's a fantastic deal! I already have an NX100 and a couple of NX lenses so this was a no brainer to upgrade to.
It came in an original sealed box, though since it's originally Korean market the 5V adapter plug won't fit a North American power socket (which you can fix by grabbing a cheap travel adapter, or potentially use another USB charging source if it has enough capacity).
http://www.ebay.com/itm/331163769379![]()
Best part for me? Comes with a copy of Lightroom 5, which I was totally not expecting! I made the decision not to upgrade since I already have version 4 and my hardware is not quite good enough to run version 6. However, that meant having to use the DNG converter for my 70D which was getting to be tedious.
So very pleased overall. 
... I also bought a couple adapters for it - FD to nx and EF to nx so that I can use it with my other lenses 

