I think you're looking at around minimum $400 for the entire setup. And that's just for your basic rack. More $ for aerodynamics, bigger racks, coffins, etc.
I'm looking into this now for my Impreza. Shit's expensive, but think of it this way - you'll never have to buy a rack again.
I'd look around craigslist too, I bet you could find a used rack for less, just gotta make sure its compatible with your car.