That's the odd thing. To provide a custom aircraft with custom parts you have to do all the analysis and testing. The person installing each part then needs the manual for that part to installing it. The creation of manuals is organic to the creation of a new aircraft. To see manuals as a separate, very expensive, line item is odd.

But we must remember a famous line from a bad movie: "You don't actually think they spend $20,000 on a hammer, $30,000 on a toilet seat, do you?" Given what this aircraft is, what it does, I think it safe to assume a high degree of vagueness and miss-labeling in the non-classified version of the budget.