You have to be a paying member to post in the
For Sale section.
When new, the Surly KM comes in a frame only and not a complete bike. It's
not out of the question but
highly unlikely someone would go to the trouble to build a KM up then sell it. So finding a used builtup KM one especially in the xlarge size probably is not going to happen.
However, there is hope.
Try this Surly forum site for a possible seller:
http://forums.mtbr.com/forumdisplay.php?f=111
Try
ebay
Personally I would just buy a new KM frame and build it up myself.
New colors for the KM in 2007: Karate Monkey - brown goes, Husker Blu is new, black remains
So if you want the Brown frame you better hurry. (My Favorite.)
Gene with Spicer Cycles runs an honest business and has excellent prices. He will do a KM build as well.
The KM frame only costs $651.45 at
Spicer Cycles.
However, frame only at
Edina Bikes has the frame for
$430.00. 
That is a great price!!!!
You will not beat that price for a Surly KM frame!!!!
OMG, where's my phone?!?!
Better order soon before the price is changed like before when they were selling the complete Cross Check for $702.00 but now increased to $875.00