here are a few great options...
LSA .5 $499+s/h. check out audiogon.com. I have a pair and they are really nice, image well and are pretty balanced. You can upgrade to the LSA 1 which has a larger cabinet and woofer for $599.
Also, the Wharfdale Diamond 10.1 for $349 are a steal. Had a pair and sold them when I got LSA's. I was able to get my LSA's new for $300 as a closeout so I gave my Diamonds to my GF (still get to enjoy them when I'm at her place), but I would say the Wharfedale's are a little more fun to listen to. Maybe not as detailed but a little more punch in the mid-bass and bass. Again, look for some on Audiogon. I think someone is selling a pair for under $300.
Also saw a paid of new PSB Image B5's on Audiogon for under $300 and a pair of Mordaunt Short Mezzo 2's for $350 that used to retail for well over $500 a pair. You can also sometimes find the Mordaunt Short Aviano 1 or 2's for under $500 now as closeouts as well as the Monitor Audio RX1 and RX2's for under $500 now.
Another speaker to consider is the Kef Q300 or Q100. Accessories4less.com usually has them for around $400 (Q100) and $500 (Q300).
All of these are either slightly used, or new as closeouts and most initially sold for well over $500. Sorry that I'm not narrowing down much, but they're all great products so I'm sure they'd all work. If it were me I'd probably look at the Mezzo 2's or PSB's and then take the extra $$$ and start saving for an SVS SB1000 to add some bass. Good luck.