Newegg offers the G.SKILL 4GB Ripjaws Series PC3-12800 DDR3-1600 204-Pin SO-DIMM Laptop Memory, model no. F3-1600C9S-4GRSL, for $43.99. Coupon code "EMCPAPA35" cuts it to $39.59. With free shipping, that's $4 off list price and the lowest total price we could find. It features 9-9-9-28 timings.