You have a lot of choices
In affordable speakers in the $200-$400 range there are speakers like the Paradigm Atom and Mini Monitor, Acoustic Energy Aegis Evo 1, PSB Alpha and Image B15, B&W DM303 and the Epos ELS3. If you can stretch your budget another 50 bucks you can consider the B&W DM601S3, PSB Image B25 or the KEF iQ3. If you are willing to shop online you might consider some speakers from Ascend Acoustics, Axiom Audio and even Omega. I'm sure I've left some out even with all these. The real point is take your time, do some research and then get some of your own music and do some auditioning. Trust your own impressions the most and make sure when you do make a purchase that you have return privileges. Very often speakers will sound much different when you get them home than they did in the store. The used market is also a possibility but when you're just starting out it is sometimes better to buy new at first, then as you become more experienced and knowledgeable consider used. Well I hope this helps you out and best of luck with whatever you decide.
Gary
P.S. If it were me I'd probably start my auditions with the Paradigm and Epos speakers. They're in your budget and I think they would be very suitable for your room.