I recommend against any consumer-grade computer. Unfortunately most business-end ones are more expensive than your budget. Therefore my recommendation is to get one lightly used or a demo / floor model.
I got an HP elitebook folio 9470M with a 256 GB SSD for $480 shipped, and I love it. It has an i5, but you can get cheaper ones with an i3. They came out about a year ago, so they are usually available for a really good price.
exitfire, I used to be a lenovo / IBM thinkpad certified repair technican and have worked on at least several hundred or maybe a few thousand of them. I have many complaints, if you'd like to hear
I'm not saying I wouldn't recommend one, but they are far from the "gold standard" that some of the THINK-fanboys would like me to think. But I prefer fujitsu anyway.