I consider air cooler with performance similar or higher than pre-built water cooling kits as high end. Coolers like Thermalright Silver Arrow, Noctua NH-D14 or even the cheaper True Spirit. Which is only £26.
Then again, if you are not overclocking no need to get higher than the Arctic Cooling coolers, they do a great job at being much better than the stock cooler. Over 25% overclock on higher end CPU, you should be looking in the higher end direction or watercooling.
Edited by ΓΛPTΘΓ, 01 February 2012 - 14:17.