sent you a pm. I don't use this machine for snow removal so enclosed cab not important to me. That said, doors wouldn't be hard to build out of 1" square tubing and lexan or vinyl if you can't find aftermarket ones. Heaters are cheap to buy and easy to install.
Very few Toolcats on the market for under $20k - let alone under $15k. I've always found that hours are not as critical as how a machine's been maintained. I've seen newer skidsteers with 1/3 the hours in a lot worse condition. This one does everything it's supposed to do with no known issues. Fires right up in the cold and runs great.