Is it worth it to buy 2GB of RAM for my Macbook from OWC (macsales.com) for $220? I heard that they have quality RAM and that is why the price is so high. Thanks.
OWC is a reputable company who has been supporting Macs for over a decade.
Other often-recommended vendors in the USA are Crucial and Data Memory Systems.
I recommend that you do stick with a reputable company that tests and guarantees compatibility with your Mac specifically, and offers a no-cost return if it doesn't work (no restocking fee). Unless you have the confidence and time to do your own testing, I don't recommend installing low-cost, PC generic RAM.