Most Koolance kit costs above an beyond. I mean, per compression fitting, they are around £10 per item - ie you need 2 for it to work, so each fitting is effectively £20. That makes these blocks seem cheap by comparison...
The only Koolance kit I've ever gotten my hands on is top noths kit. Well manufactured and finished. I'd certainly seek out there kit over, say, some like XSPC's or EK's. I'm probably being a bit harsh on EK there, but Koolance's stuff is generally just that bit better finished...
If I'm honest I think all water cooling kit is overpriced by about 20-30% for what it is. I'm hoping that a bit more competition would drive down the costs a bit, but instead it seems to be making the market more and more expensive.
There's something to be said about going back to watercooling roots... or going DIY with standard plumbing parts...