I realize you specified active monitors, but if you are open to passives, this is a potent combination, and it meets your price point.
http://www.sweetwater.com/store/detail/Monitor1mkII/ http://www.sweetwater.com/store/detail/Servo300/ Oddly, the Alesis power amp(RA150) that Sweetwater currently has on hand is a poor choice for these monitors. It is grossly underpowered for them.
The Samson Servo300 is a good match.
These monitors have plenty of low end, but they are rear ported, so placement is inportant. You don't want to set them too close to a wall.
I've had mine for a few years, and I still love 'em.