As I write this, I am listening to Axiom M3Ti's and feel that they quite capably meet your requirements for $275 shipped (new, ~$150 used). There was a lot of hype about these speakers about 2yrs ago, and it was well-deserved as these are solid little monitors.
They are remarkably well made at this pricepoint (very well-done laminate) and sound fantastic. I am using them in an office system driven with an Audio Refinement Complete integrated (50WPC) which is actually overkill. They are rated at 93dB/m with an easy 8 ohm load.
When I bought them about 1.5 yrs ago, they actually bumped my main speakers for awhile because the highs were far smoother and less-fatiguing than my old B&W's. They have impressive resolution, probably owing to the fact that they do not use a crossover - the 6.5" woofer naturally rolls off, yet blends surprisingly well with the titanium tweeter. You don't get much below 50Hz, but it seems like more with a punchy midbass.
This little system has an enjoyable presentation of most kinds of music - female vocals, jazz, chamber and acoustic music. It can even get you toe-tappin' with rock, but only in a small- to medium-sized room.
I have no affiliation with Axiom, and to be honest, I was seduced by the reviews. The only speaker that I demoed them against were B&W DM601s2's and it was an easy decision - MUCH better highs, a sweeter, more engaging midrange and much more refined. The B&W's were a little quicker, which was great for rock if only I could get past that hot tweeter. Needless to say, I am very pleased with my choice despite the relatively blind decision. Here's one of many reviews to give you a little more background on the design and the company's background:
http://www.enjoythemusic.com/magazine/equipment/0402/axiommillennia.htm
Good luck with your system - it can go a long way towards making those hours at work seem far less tedious. Mark