What country are you from btw? I know EU, but it may differ.
EDIT: Nvm, found it in hidden in the comments :S.
---------- Post added 2011-05-04 at 06:00 PM ----------
About your question on RAM and why some 2x2GB is cheaper than others.
There are 4 main contributing factors.
1. The amount of MB on the ram chip(s).
2. How many chips the ram is spread on. This one not so much.
3. The speed (In MHZ).
4. The CAS latency. I completey forgot what it was short for. But it determines how fast your RAM starts to work.
I suggest : 2x2GB - 1333 MHZ - CL8 (8-8-8-24).
You should get that for about 50-60€.