Computer memory as high as 8 GB online

Technology sure seems to be on a warp drive nowadays. I bought my apple Mac book 6 months ago with an up to date memory of 1 GB which is the standard back then, but just last month, I was shocked that there were computer memory being sold that were as high as 8 GB already ! I want my computer to be as fast as possible since I was a gamer in the net, so I decided to upgrade my laptop memory to at least a minimum of 4 GB but I also wanted the lowest possible price for this memory module. I found one such site in www.memoryupgrad.pro where they have all kinds of modules including an Apple memory which is exactly what I need for my laptop and this is a such great find for me.