Yep, it's a ridiculous (IMO) $8,000. I say that because the body alone costs more the the Pentax 645z with includes the same/similar 50MP Sony sensor in the IQ350. To get that from Phase you've gotta add another $30K+.
I don't expect many will be buying a body by itself. It is significantly less when bundled with a back, or when upgrading from a DF/DF+. Also you're significantly off on your pricing for a CMOS version.
An XF IQ150 kit with Schneider 80LS lens has a list price of $32,990. Alternatively the IQ140 kit with Schneider 80LS has a list price of $20,990. And upgrade pricing is available from nearly any previous medium format system.
Either way a P1 kit provides several major advantages over the 645Z:
- a line of 10 modern-design autofocus Schneider leaf shutter lenses with flash sync of 1/1600th*
- very fast, robust, and professional tethering
- support in Capture One including their world-class color profiles
- retina touch screen interface with the best set of image review tools on the market including focus mask, exposure warning, raw-file clipping indicator, zone exposure heat map, draggable guides, and toggle-able black and white review mode
- automatic perspective and keystone correction
- advanced body features such as the seismograph mode
- waist level viewfinder (including spot metering and autofocus)
- built-in wireless control, review, and editing (IQ2 and IQ3 only) with fast speed and native integration
- professional support with knowledgable dealers and options to purchase with a 5-year warranty that includes free loaner during any repairs/service.
- wide network of rental house, digital tech, and assistant availability and knowledge
- compatibility with view cameras and tech cameras
The 645Z also has some unique advantages like weather sealing. I'm happy to take an XF kit into light or moderate rain but I would not step under a water fall with it or take it into a hurricane. It also has multiple AF points, though they are very close to the center of the frame, limiting their practical utility. Each system has its pros and cons, and the price of entry for the 645Z is clearly a big pro for that system.
*The 240LS syncs at a "measly" 1/1000th.