Zeiss does not make bad riflescopes, nor does it make any cheap ones.
Some are comparatively (~$400 as of February 2010 for some Conquest models) affordable and some are sufficiently expensive to contemplate selling a kidney.
Overall, if you can afford a top of the line Zeiss, it is about as good as a scope gets.
My personal favourites are Zeiss Victory 1.5-6×42 and 2.5-10×42. For low light, check out 3-12×56 Varipoint.