Patriot Viper 3 16GB PC3-12800 DDR3 Desktop Memory (2 x 8GB) for $59.99 shipped.  Here is a screenshot for your reference.  For the technically inclined, this dual channel RAM operates with 10-10-10-27 timing at 1.5V, which makes it compatible with most standard systems.  Most places have this set of RAM for about $72.