Or, more likely, its a high-margin item for the camera manufacturer.
It is. But when you make the best, you can charge whatever the market will bear. It is, however, a very niche market because of the cost involved. Just think of the R&D costs involved in this, let alone the manufacturing cost for a 645 CMOS sensor on it's own.
I have a 6x6 film camera (Bronica SQam, 6x6, 120 film) that will produce enlargements similar to this thing, but could I afford to go Digital? As it's not the camera that brings the money in, no. You are looking at a real-world $20-$25K to get a decent setup in Digital MF. It cost me a LOT less. Even today you can pick up a minter for less than $500. So why would you go Digital? Speed, plain and simple. The new digital systems are a LOT faster, and far more versatile. If your job or income depends on it, you can easily justify $25K on a new setup. And when you factor in the cost of buying, processing and converting film to a quality digital format, the camera WILL pay for itself.