I haven't priced them in a while but I bought my identical Kioti CK20 (2004) used with thirty hours on it plus loader for 10K from a dealer back in 2005. That was about two thirds of the new price. You say the CT122 has no attachments...no loader??? What about HST?
Absence of a loader would knock quite a bit off the price as most people want the loader and a replacement loader would probably cost $3K. The problem with the CT122 without a loader is that it is a relatively heavy tractor and has only a two range HST. That means it is not the ideal mowing machine (virtually any Kubota in that size range would be much lighter and better as a dedicated mower). The Kioti and Bobcat tractors excel as all around machines but that means that a loader is needed.
My estimate of private party price for 2010 CT122 hst without loader with 200hrs would be about $7k. With loader about $9-9.5k. Same as equivalent Kioti CK20s and maybe $1500 less than equivalent Kubota.