Depending on where they are they can likely get a monthly rental on a Deere 350 for around 15k-20k. Probably even less since it's in the states.
It isn't a very efficient job though. Having that rock truck there is a money pit, I'd just bring in a bigger hoe to dig and have that cast dirt to the 350 who could throw it to the dozer. Or just use the hoe and the dozer since he's just waiting around most of the time anyway. And the guy digging is hard to watch, it's like he's doing it in slow motion.
That's all assuming they care though, which given the entire premise here, I don't think they do
