A couple of years ago, my dad bought a Gary Fisher bike for about $400. I don't recall the model, but I'm sure it's discontinued by now. My mom gave him a hard for spending so much on it, but, having taken a few rides on it, it was so much better than the $250 department-store bike I bought around the same time. There's just no comparison between the feel and ride of the two. I try to sneak rides on his bike whenever I can
We didn't spend as much on mine because I was "going to ride it at college" (which I never really did), and now I kinda wish I'd spent a little more then to get a better bike. My advice is, spend a little more, and get something that you like, that fits your needs, and that rides well. You'll be glad you did.