Back in 2008 I had my current van shipped from Portland to San Diego. (I know--with all the early vans in Southern California, why did I have to go all the way to Oregon...?!) I got prices from these places. All prices are from 2008 except the $650 I just got from their web site.
Direct Express Auto Transport $650, more if a rush, more if it's not running, doesn't steer or have brakes. For not running, it was $875 back then. Price of gas at the time factors into all quotes.
Their web site has an online calculator so you can get a price without having to call them:
Express Auto Transport $655
1-800-405-0914 (Better Business Bureau)
Interstate Auto Mover $825
All American Auto Transport $750 + $150 = $900 (two different trucks?)
Official Auto Transport $550
"Door to door, same truck"
I went with Magic Carpet Auto Transport $689 (w/insurance)
I don't recall exactly how I made my decision. I think a lot had to do with how together they sounded while getting my quote.
All of these were on an open trailer. It costs a lot more if you want it in an enclosed trailer.