Bookshelf speakers on a budget

+1 Paraneer.  I believe all previous recommendations to be sound (no pun, well maybe). Mating speaker with amp is paramount to getting top value from both units. Value of a speaker is highly subjective. There are many good possibilities in your price range, new, discounted, used. 

I use Wharfedale 10.2s in my office system and they sound fine even in a less than optimal setup.  I can tell you that they will react to better upstream components.  Before I brought them to the office, I hooked them up to my home system and was amazed at how musical they were.  If you feed them well and take care in the positioning, they will respond.

Thanks for all the suggestions everyone. 

Easy, LSR308

Elac Uni-Fi UB5. Nothing comes close for the money.