and they're not too expensive, especially when you consider that they come with multiple top-notch amps as well. if you work it all out, they are really quite a bargain.
15k for a three-way speaker, with the best mid-range in the world, a 50 liter enclosure, one of the best crossover networks available, and *six* seperate power amplifiers driving each driver individually. not cheap, but very reasonable.