Holy cow, the cost of a 7" beryllium midrange driver has to be ridiculous. According to Focal, truextent beryllium foil from Brush Wellman costs more than it's weight in gold.
I know this sounds crazy for a speaker retailing for $7000 (in the case of the Persona B), but it really seems like they must have skimped somewhere here, maybe in the crossover or the cabinet, to still maintain dealer profit margin ratios, unless they are going to sell these internet direct...