I get the appeal of wanting to shoot Instax film on a camera where you can have control of the image's exposure and DOF through aperture control. But, $470 or whatever they're charging is ABSURD. They look a lot more like a plastic Lubitel than a Rollei.
For comparison, I thought it would be cool to shoot Instax film on an old manual camera, so I paid $35 for a Busch Pressman 2x3 with 11 film holders, $20 for an Instax mini camera, and $13 for two packs of film. I can load the film in the holders, expose them, an load them in the camera for processing. So, for $65 I have a very nice way to shoot Instax film. It's a little more tedious than just popping in a cartridge and shooting, but if it saves me $400, that's fine.
Plus, I can shoot actual film with this thing so it's so much more versatile. That's a lot of money to spend on a 1 trick pony.
Now, if someone would make an instax back for 2x3 cameras...