As I understand these IVAS headsets bear very little relation to the commercial hololens devices. I'm not saying Microsoft aren't doing this for a healthy profit, but there's a significant amount of engineering work for relatively small production numbers, and most of it would not be transferable to the consumer and business segment hololens gear. At least initially probably blocked for sale to other friendly militaries as well.

Even simple things like repackaging and ruggedising COTS hardware to pass shock/vibration standards, weatherproofing it for a range of adverse conditions, etc. is a reasonable cause to add "military grade" markup.