I've got either 1866 or 2133 in mine I believe... can't quite recall. it was the fastest DDR3 at the time, latency of 9-9-9-27. like $75 maybe.

EDIT: I was totally off. Crucial Ballistics, 2x8gb DDR3 2133, 10-10-10-32 and I paid $98 for the pair about a year ago.