I just checked, and the kx161 uses the same door. A new one is $6600 canadian.
The poster is in UTAH.
The $6,600.... Canadian would equate to $5,000 in Utah, though that is certainly not cheap either.
I also think it extremely unlikely that he will find a used door for his machine, before the snow files in Utah, and maybe MUCH later.
I wonder if a good body shop welder could do a satisfactory or temporary repair on the damaged door?