Yeah, that's a pretty good description.
So what you need to do is decide what kind of sounds you want, or what kind of music do you want to create.
If you just want realism, like piano, strings etc. get a rompler. if you want more original "electronic" sounds ie; techno, trance etc, get a VA synth.
I have quite a few synths and have played with most of the ones I don't have. And if your interested in a VA synth, I reccomend checking out the korg ms2000. You could get one used for about $400, I'm guessing. It's one of my all time favorites and definitely a best buy for the money.
I'm sure someone else around here could give you better advice about romplers than I. I have a few, but the ones I'd reccomend are quite a bit above your specified price. Your best bet is to goto a store if you have one near, and find out which ones you like, and then hunt for them on ebay.
I advise getting something newer and preparing to spend at least $400 to get a quality synth that you will like.
