Sub plate-amps in the UK

[Helix]

yeah, those BSB plate amps look real tempting, i am currently designing another sub and planned to knock up another amp out of some parts i have kicking around to power it, however when i look at designing the active filter with ajustible phase as well, i think i might go for the plate amp, any one know how much the 300 or 500 watt ones cost?

also i thought the power specs were i bit interesting, i see that for the 200 watt one they sell 2 models, one for 8 ohm, one for 4 ohm. I unfortunatly have a 8 ohm 500 watt(rms) sub.