Legit Reviews posted a review on the Kingston HyperX Predator 8GB 2666MHz DDR3 Memory Kit

The new Kingston HyperX Predator memory kits range in speed from 1600MHz-2666MHz and are available in 8GB, 16GB and 32GB kits of 2 and 4 modules. Kingston already has nearly a dozen HyperX Predator kits shipping and the series just launched last week! Right now 8GB (2x4GB) dual channel kits are the most popular sold, so here is a list of the five HyperX Predator kits that are available:

HyperX Predator 8GB 2666MHz - CL11 - KHX26C11T2K2/8X - $188.00
HyperX Predator 8GB 2400MHz - CL11 - KHX24C11T2K2/8X - $67.00
HyperX Predator 8GB 2133MHz - CL11 - KHX21C11T2K2/8X - $65.00
HyperX Predator 8GB 1866MHz - CL9 - KHX18C9T2K2/8X - $64.00
HyperX Predator 8GB 1600MHz - CL9 - KHX16C9T2K2/8X - $56.00

As you can see Kingston has a HyperX Predator kit for pretty much every popular speed grade from 1600MHz to 2666MHz in an 8GB dual channel memory kits. The prices start out at $56 and slowly rise an average of $4 per speed grade, which is very fair. The top end kit that is clocked at 2666MHz with CL11 timings carries an MSRP of $188. This is $121 more than the 2400MHz kit! At nearly triple the price of the next kit down, you are seeing what happens you want the very best kit available. Kingston is currently using Samsung ICs on these memory kits and it is very hard to get 2666MHz memory kits through the binning process. We would assume that less than 10% of the kits would run at such high speeds and this is what is driving the price up.

  Kingston HyperX Predator 8GB 2666MHz DDR3 Memory Kit Review