So the only reason they can build this and not have to conform to pollution laws is because they're using remanned Cummins 12v engines. There's a limited number of those in any case. As soon as they have to conform with new engines, they're going to get a lot more expensive.
Caterpiller stopped providing truck engines for a decade rather than R&D a compliant motor. That was the second largest truck engine manufacturer in the world, decided it was too expensive to bother, which tells you how much these engines cost new.
I love the idea of this tractor, but it's not going to survive the economy of scale intact.