This is the lowest price I could find for a 4gb kit
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148191
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148191
This is the lowest price I could find for a 4gb kit
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148191
take your macbook and receipt to an apple store within 14 days of purchase. tell a manager you wish to participate in the apple ram buyback program. they take the machine (technically they buy it from you), yank the ram out, send it back to apple, and sell you an additional 4 gigs for 150USD, the same as what it would cost to buy it from the apple site directly.
perhaps mac rumours members could pool up and create a giant pile of 2GB chips as they are pretty much useless.