Those are full rangers, probably fostex woofers. Those drivers are reasonably pricey. Add in a about $200 for any given cabinet, and the prices aren't too bad if you think about the labor involved.
(I just checked, they are fostex drivers and they use black hole 5 for dampening, which is pretty pricey stuff too. 10 yr warranty is something you don't get by building it yourself. Wow, that's not too bad. The Fostex 8" drivers on their high end model cost between $150 each to $400 each depending on which one they use. I doubt it's the $400 one, but still a pretty good chunk of what you pay goes towards the driver, which is not the case in tons of speakers I've seen. On the other hand, there's no crossover cost. Wonder why they don't add a supertweeter.)