This is a good point - I have no idea the turnaround on profitability for a low volume/high margin item. Is 10 years generally accepted, especially given the depreciation will make the secondary market very attractive to buyers?
It's not just a single product here. It's s whole product line that is the real investment here. The price for creating a single product is then relatively low compared to the R&D put into the drivers (especially the coax) that get used all over the place. The Kippel can be used for all products, and for a company like KEF, is a no-brainer. It easily takes away work for 2 people, so you have your money back within a year or so.
I really doubt that any of the products are sold as a loss, and I also doubt that the R&D effort to create the flagship product is very much higher than for the Q or R series, since the major investment is joint technology. It's definitely not as reflected in the sales price difference. So yes, these things are too expensive for what you get. But as always with these things, if you want to squeeze out the last percentages of performance, you'll pay a high premium for it. Price is also determined by what people want to pay for it (and the competition), and evidently, people pay for it.