If you can stretch your budget a little, give a listen to Paradigm Mini Monitors -- great bookshelf speakers for the price. Their quality will allow you to listen at low volumes without losing much. They MSRP for $399, but most authorized Paradigm dealers will give you about 15% off. Of course, stands will run you a few bucks too.
You might also do some research on Ascend CBM-170's -- $328/pr. They are sold only through an Internet company (Ascend Acoustics). I've never heard them, but I've read nothing but good things about them.
Finally, for well under your budget you might want to give a listen to Athena speakers -- AS-B1 or AS-B2. I understand they are good speakers at their respective price points.