I'd also go with corsair, a more renowned brand, Crucial is really renowned for good price RAM, so I'd go for Corsair if you're looking for performance:reliability!
Norway is a very expensive country. Here the Corsair 1 GB RAM costs 149 dollars (x 2 = 298 dollars) and one Crucial BallistiX 512 MB 90 dollars (x 4 = 360 dollars).
So in Norway the Corsair RAM is pretty cheap although in the US or UK it might be expensive.