There are two ways to recoup R&D costs.
1. Sell many units for cheap.
2. Sell few units for a lot of money.
Now of course I do not presume to speak for Theoretica App. Phys. here but I do note from reading many customer testimonials that this product is not like anything else in hifi, i.e. you plug it in and it works as you would expect. Some measurement and setup is required and there may be a learning curve (though I would expect that the learning curve would be less than say, implementing Dirac or running Acourate or even building your own PC). Therefore some level of customer support is required. From testimonials, and from my own correspondence with them, I know that their customer support is excellent. If this product hits the mainstream and they start selling many units, this brings with it its own problems with sourcing parts, assembly, scale, hiring support staff, and so on. They MAY decide to remain a boutique operation with high prices and providing high level of customer support to fewer customers than to sell it cheap and deal with a deluge of customers.
Speaking as a soon-to-be customer, of course I would love to pay less, but not if paying less is unsustainable for this company. Theoretica are not like a DAC manufacturer where there are hundreds of companies to choose from and it doesn't matter if a few dozen of them go under. These guys are the only ones with this product.
Also, something like BACCH undermines the hardware fetishisation that is endemic among audio enthusiasts. Spending 5-6k and then needing to set up an esoteric, bleeding-edge DSP software (the effects of which are not the result of some plug-and-play physical box) with in-ear microphones and head tracking is a non-starter for many people compared to the instant, physically-tangible, gratification of buying a 6k DAC with shiny LED-lit glass marbles.