Microcenter has 4gb sticks for $19.99, $10 off the normal price. I could not find them on the shelf and had to have someone go get them, might be because they have their brand of ram on sale as well.
http://www.microcenter.com/single_product_results.phtml?product_id=0352108
http://www.microcenter.com/single_product_results.phtml?product_id=0352108