Considering I (& AC) initially offered the first revision of this block to the general public about two years ago (when it wasn't quite so outdated a design and was the first true production silver waterblock) it's easy to knock.
As far as I know, there's a new micro-channel design on the way into the AC range which I'm sure will inevitably be offered in .925 Silver too.
/my €0.02
[Edit] found a year old thread with the original price difference quoted here -
http://forums.procooling.com/vbb/sho...14&postcount=7