Depends on what the Undercarriage is like. With tractors this big, a set of new tracks for the machine can be quite costly so that really determines everything else. Hours also is a huge factor as these are not cheap engines to rebuild. Having a cab, or not also makes a big difference on value too. So honestly there is no real answer as there is not enough information.
Just off the top of my head to give you some idea, I would say with decent tracks, a cab, 10,000-12,000 hours, will probably value around $35,000.
They are nice tractors though for sure. I have kicked the tracks on a few myself...