Kingston HyperX 16GB (4 x 4GB) PC3-12800 DDR3 Memory Kit $64.24 shipped AR at Newegg
Newegg has the Kingston HyperX 16GB (4 x 4GB) PC3-12800 DDR3 Memory Kit for $104.99 - 15% off promo code APRMEM15 (Exp. 4/8/12) - exclusive $25 rebate = $64.24 with free shipping. Features: CAS 9 latency. NEWEGG

Next lowest price on PriceGrabber is $122.27.