MXR M82 Bass Envelope Filter $110 shipped CONUS
Incredible Analog Envelope Filter that features a separate mix of the dry and effect level to really get a big unique sound. This one can get very synthy if you set it right.
Check out the video review by Ed Friedland about this pedal here: http://www.youtube.com/watch?v=opKs5ZGqVpg
Comes in original box with all paperwork.