I agree with the others. Let the owner put a price on it. He also says it runs, so have him put a battery in it and attempt to start/start it for you. I don't see a three point on the back.
It is still a diesel. And I've seen alot of diesels sell over the years, and have four diesels myself. The paint and tires don't look bad. Has a mower deck. Appears complete. Is missing some tin on the muffler, not a big deal. How many hours does it have? These kubotas will run for thousands of hours with proper maintenance. Pull off the tunnel cover and check the driveshaft. Diesels eat driveshafts. To rebuild it, parts from CC will run ya a couple hundred. Take a 9/16 wrench with you and check the bolts going through the frame into the rear case. They tend to loosen and strip out. If it runs good and the driveshaft isn't toast, it would be a steal at $1000. I've seen alot of comparable 782D's running sell for $1500+. Something about those red smokers. Nonrunning, still probably $750 since it's a diesel.
Just my
worth.
I hope for you he doesn't know what he has. If he does, he's probably trolling and hoping you offer high dollar.
Good luck and keep us posted.