I've owned four Tuckers. One of them was an ex-ski area machine and it was by far the roughest. Personally, unless the machine was an "incredible deal" I wouldn't buy another snowcat that was owned by a ski area, or otherwise used as a groomer, and this machine isn't an incredible deal...not even at half the price.
Tuckers of this era are really pretty simple machines, but parts add up uncomfortably fast. Everywhere you look on this Tucker there are "issues", and these are the ones you can see. I'm virtually certain you'll find other problems once you get into it. Look at the quality of the workmanship on the repairs. The wiring is atrocious. Look at the fuel line coming out of the carburetor. Does that look like someone took any pride at all in their work? Now extrapolate that "quality" throughout the rest of the Tucker.
RedSqwrl mentioned this already, but I totally agree with him that different people have different uses for their machine, and different objectives. If you don't care what it looks like, and you're always going to be close to home and are content to have mechanical breakdowns, you can get by with stuff others would replace. If your goal is to have a machine restored to original condition, or one you are going to take deep into the backcountry, this would be a very expensive specimen to start with.
Either way...I'd pass on this one. I genuinely believe you would be better off with a different machine. It might cost a bit more to purchase, but it should be in much better condition and needing much less reconditioning.