Buy these: http://www.amazon.com/KRK-RP5G3-NA-Generation-Powered-Monitor/dp/B00FX7MMRO/ref=pd_cp_MI_0
Just your budget, and some of the best speakers for that price
Also consider these:
http://www.amazon.com/PreSonus-Nearfield-Studio-Monitor-Stands/dp/B00CQBMDZQ/ref=pd_cp_MI_0
Both of the pairs have amplifiers in them, consider them like the audioengine, but better.