Some of the car rental places rent trucks. 1/2 and 3/4 ton. I wouldn't do the car dolly. I would do the U-Haul auto transport. I've used them a number of times with good results.
The other thing to consider gas prices. Most trucks pulling a trailer and car will get maybe 10-11 mpg? When I sold my C10 the buyer used Reliable auto transport enclosed trailer. They were on time and went very smoothly.
Don't forget since the cost of diesel is above $7 per gallon . The fuel surcharge the trucking companies add to your bill will be noticeably more expensive . Some companies are charging almost $2 per mile or more
I think you can get an instant quote from Uship, right on their main page, but i would consider that just a ball park figure. I have used Uship with good success to ship some trucks and equipment. Just if you go that route, stay away from brokers. Use independent people, check their feedback, and mostly based on just their name alone you will be able to figure out if they are a broker or not. Like stated above, i think the price of fuel is going to really put a damper on shipping things like this across the country. I am currently in the market for a Ram 5500 cab and Chassis, which i would normally just search the entire country for, but im limiting my search to within a few hundred miles of me, since i know its gonna be thousands to ship a truck across the country.
I just did a little math.....Phila to LA in a 10mpg truck would be about $1900 in fuel.......lol