The
Hsu Research HB-1 mk2 are on sale right now, they are a terrific bookshelf speaker, and 300 will get you a pair shipped. The
Behringer 2030p is pretty highly regarded, and they can be had for much less than 300 shipped. You can also get it's big brother for 300, the
2031p, if you want something with more bass capability. If you can handle their 4 ohm load, larger size, and heavier weight, they make for a great bookshelf speaker. If you want some real bang for your buck and don't mind doing a little work, check out the
speaker kits they have at parts-express.com, they are easy to build and look like they would sound real nice.