Patriot Viper II Sector 7 Series 12GB PC3-12800 DDR3 Desktop Memory for $49.99 shipped after this $30 rebate.  Here is a screenshot for your reference.  For the technically inclined, this triple channel RAM is XMP-ready, RoHS compliant, features lightweight aluminum heat-dispersing shields, and operates with 8-9-8-24 timing at 1.65V.  Most places have this set of RAM for about $77 or more.