you can email Bill Allen ( www.baulsaudio.com ) for the U.S.- price of the baffle- kit only.
Which 15"- drivers and which active crossover/power- amp are you using? Please regard that the efficiency of the Prometheus- wideband is at 100 Db/1W/1m and not every woofer will work together with the widebands sufficient. The deal is the behaviour of the woofers in the crossover- range. O.B.- woofers can sound very clear but they also have low efficiency and the amp needs to control the resonance of the woofers - when you post or mail me the datas of your setup i can give you advice if the combination with the Prometheus- baffles works.
Regards
Robert Bastani