I have so far only seen these for pre-order at CPUCITY for £387.

***MUST...NOT.....ORDER....MUST....STOP....SELF... ..MUST.....SAVE.....FOR.....NEW.....CAR***

With the evolvement of the new nVENTIV Mach II ST system, nVENTIV offers you extreme performance at a low cost. This new version of the Mach II has the same awesome cooling power as the original and approved Mach II but at a cheaper price. The product is avaiable in both the Enlight and Lian-Li design cases.
nVENTIV Link
CPU CITY Link