Hey guys, I'm a Mac newbie and I recently just purchased an iMac MC812LL/A 21.5-Inch from around Mid 2011. Love the i5 Quad-core but it only comes with 4GB RAM. I've read I can have as much as 16GB which would be great. I also heard that Apple charges you out the ass to upgrade so I was wondering where the best place to buy the new RAM would be and where I can get it installed (or I guess I can just figure it out for myself to install it). Thanks.