If the operating hours bear out on inspection, that is quite and interesting little machine. Of course, it is actually early 90's, not early 80's as posted.
Yes, price in an open sales seems a bit unrealistic, but time and an interested buyer will tell.
The hours are unusually low and are frequently attributed to broken hour meters. Just like good low hour cars, these tractors can be inspected for some logical alignment to the hours. Is the wear on the foot pads consistent with 3-5 years of use? The control lever knobs? Front steering tight? Etc.
A few years back I picked up a '91/92 4020 with about 225 hours showing. That is hard to believe. When I went to inspect it, the original owner (1 owner with receipts) has .25 acres of mowable grass ... mostly under thick shade and sparse growth at that. Good sign. The plastic knobs have no real wear on the graining patterns. Etc. Etc. I bought in at their asking price. When I took the RM48 deck off, I touched it with a damp scrub brush to find original powder coat paint covering not less than 85% of the underside of the deck. This tractor had been used maybe 10-15 hours per season with mowing and another few hours to plow a 30 ft driveway. Put away clean and stored always indoors.