If it's a commonly traveled route, like coast to coast, it's actually cheaper than a route a little more off the beaten track. Also, if you want door to door, thats more expensive than terminal to terminal. Last time i shipped a car to europe, it was about 1/2 the cost of shipping a car from here in PA to California. That was with me dropping it off at the shipper, and the car being picked up in port in Europe.
If you are hauling only one or two cars in an enclosed trailer, the cost is going to be appreciably higher than a guy hauling 6-8 cars on a big semi. On the higher end cars, I'm willing to pay the $$ diff to get that "personal" touch of a 1 or 2 car enclosed hauler than the cheaper guy with the contract driver with 6 other cars on the trailer.