Hi Dig,
I know but as I've said earlier, I have no idea. This is a nascent industry. I've no idea how many staff DoD would need to add. I don't know the pricing for, say, NAC equipment. I don't know whether Wave's service is, more-or-less a standalone system, but it looked that way in our previous experiences of major sales. Wave's services haven't previously seemed to be offered as an element of a larger order. And TPMs wrap themselves around a PKI architecture.
Going one step further (unlike you), I still think that seat count is the only viable way to derive a decent estimate. Here's why. By my calculations at the time, I guessed that both GM and BASF had close to 100% penetration rates. I think PwC is doing the same: they have around 150,000 people and they are switching on 150,000 TPMs. So - perhaps naively - I expect the same at DoD, if indeed they purchase Wave's software. In a PKI system, I would pretty much assume 100% penetration is necessary if you wish to communicate.
I understand what you are saying, though. For once we have a big number to work with. But seeing that I am suggesting that Wave appears to offer a standalone system, and there's $2bn up for grabs - I am not so completely wild as to suggest all $2bn is coming to Wave! Instead, I expect DoD will come in under budget.