It's a money pit because the only way to get spares is to find a junker (and even then all the rubbers will need to be replaced with whatever you change out) or to machine them.

This is a 60 year old car, it's not like you can walk in to your local car part store and order some parts. You're going to be buying your parts from places like this: http://www.willysjeepparts.com/ which will happily charge you a good sized premium for the parts because they're being made in much smaller series than for cars that are still 'current'. And that's assuming you do the work yourself, if you let someone else do it for you it'll cost quite a bit more still.

They also need quite a bit more maintenance per mile driven than a modern car because the engine clearances are not to be compared with modern stuff.

But if it came to your 'prius' or that 60 year old beast and we had to cross 50 miles of bush I'm pretty sure which one I'd pick.

A prius is not a rugged car, not even a little bit, it's a delicate piece of beautiful engineering.