I think yamaha is the way to go. . .well Kurzweil is the way to go, but going to be out of your price range.

it's been a while since I looked at whats current, but yamaha's "S" synth was a killer deal. I would also recommend used for that $$ is worth considering...
I just replaced my controller w/ a cheapie M-audio one and it sucks. I feel I'm going to break it in half at any given moment.
Do you need a sequencer, sampler etc? Or just looking for sounds and keys?