Im looking to upgrade the RAM on my macbook, It came with 2GBRam & I want to add 2 more GBs... My question are what are the best brands? I dont want to end up with a bad brand like the dozens off amazon that make faulty hardware. Also, what should I expect to pay? I bought my Macbook in 2007. 13" & Im still running 10.5 Thanks in advance for the help.