Hi Lozza81,
The price tag of the 2000C7GTF kit is due to the huge amount of time and effort that goes into screening, testing and qualifying memory at these extremely high speeds. These modules are built from the very fastest ICs available, and hand-tested and matched. Very few modules make the grade at this level (and we need to find three perfectly matched 2GB DIMMs to make one kit, making it even harder) hence the price. But that's what you're paying for - the fastest and best RAM that can be built right now.
The Kingston kit you mentioned is a C8 kit, I think (although I can't actually see it listed on
Kingston's site). The screening, testing, matching process is slightly easier at CAS 8, as opposed to the 7-8-7-20 timings of the kit Hexus has kindly reviewed. Corsair actually has a
2000C8GTF kit as well, which is $100 less than the flagship C7GTF kit, because it's not quite so difficult to build. This puts it in the £330-350 range I think, at current exchange rates.
The Corsair kits come with the new Airflow Fan as standard, as you mentioned, and they all also use the DHX+ heatsink, which is unique in that it cools the face of the memory ICs, and the heat expelled from the rear of the ICs, into the PCB. The DHX+ cooler is also modular as it allows for cooling upgrades in the future.
As the review states, the 2000C7GTF isn't for everyone, but it's not a mass-market product. It's designed for extreme overclockers, and for people who simply want the very best of everything. And with the soon-to-be-released thermo-electric cooler, it's even better :)