I bought 8 GB of RAM for 40 Euro at a computer store downtown today and was offered to have it installed into the Mac Book Pro for 20 Euro. Needless to say I chose to do it myself.

Here’s how the laptop looks when you remove the cover:

The whole prodedure takes 5 minutes. Apple shows you how to do it.

And if you go to an Apple Store to have it done you pay a lot. I assume having them put it in for you will cost another 200 USD..