Kingston HyperX 8GB (2 x 4GB)  PC3-12800 DDR3 Desktop Memory Kit for $14.99 after coupon code TRX67972 and this $10 rebate.  Shipping is $2.29 for a total of $17.28 shipped.  Here is a screenshot before the $10 rebate for your reference.  This dual channel kit features 9 cas latency at 1.65V and Intel XMP support. Most places have the desktop memory kit for over $40.