Green Mountain Audio-Europa & Europa Max are in your price range. Great company and very musical. Check the forums-worth your time.
Linn Katans; apart from being dynamic and extremely accurate from the outset, they offer what few other monitors do... scalability. Katans make a quantum leap when they go from passive to active configuration... you can start with a passive system and slowly add... first a sub to fill in the base and eventually active amps. I started out several years ago with Katans and rotel amps. Over the years things have come and gone (eventually settling on an all Linn system), but the one thing constant has been the monitors.
I agree with Jay douglas. If you intend to put monitors on stands they will take up the same floor space as full range speakers. I set up a small listening using monitors on stands but always felt something was missing. Weight is a good word to describe the missing element with monitors, air is another word. Those qualities are difficult for monitors. Good luck.
The nice thing about Green Mountain Audio is that their speakers, large or small have "weight", fill a room with a huge sound stage, have great mids and highs and the bass you can feel. Read the forums. I've had several full range speakers that could not come close. Green Mountain Audio is about the music. Enjoy!
There is a pair of Sonus Faber Signum's listed in the classifieds for that price - you might want to check them out. I've had a pair for 3 years and continue to be amazed at how good they sound. I've also tried 2 floor standing speakers, Martin Logan SL3 and Audes Jazz, and I feel that the Signums are much more natural and musical sounding than the others. The Signum's are the lowest price speakers in the SF Classic line. You would want to get the SF stands to go with them, and I think they do well with good tube amps.
I have owned a number of mini-monitors: Totem, Linn, Quad, Spendor, and heard several others. While each of these has its advantages and disadvantages, my favorite, and the one I still own, is the Spendor S3/5. However, ... if you want something that has a more "exciting," rather than to my ear natural sound, these are not for you. Also, forget about low bass unless you intend to get a sub. I briefly heard the older Harbeth years ago and was impressed, but haven't heard the new one so can't comment on it. Also, associated equipment, room and music preference will make a big difference in which one you might prefer.