It may seem high but I could see well over 10 hours labor, there are a several lines to disconnect linkages to remove, pto main shaft, most likely a loader and loader frame, then splitting the tractor and separating the halves, R&R the clutch, pressure plate, throw out bearing, possible pto drive hub (if it has one) pilot bearing.
Then bring it all back together and reconnect everything. Just think if it had a cab what the cost would be.
Then consider the jacks and stands and rollers to support it all and move the halves.
It is not a fun job to do, not real difficult but pretty time consuming.
An individual doing it in a small farm or home shop would likely be a couple of days taking apart a few days getting required parts, a couple or 3 days back together and another day getting all adjusted and trimmed out.
Been there done that, not super hard but not a lot of fun either.
Some old iron was much easier, my Oliver with the bathtub frame you pulled the engine rotated a bit set it on the frame pulled the auxillary trans and had the clutch right there, no splitting required, but not many of that style still around.