Sadly, price is not the only issue. There are so many "transport brokers" out there who will promise all sorts of things but fail to deliver. The issue with them is they do not have their own trucks and when you ask for a shipping quote, they put out a request for any trucker who is willing to respond. Seldom, if ever, does the quote match the actual price charged by the trucking company. Reliability is also a huge problem. Not showing up when scheduled, changing the price at the time of pickup, etc., etc...
When I had my vehicle shipped from SC to NV, I went directly with a carrier. $1800 in an enclosed big-rig trailer - but that was before diesel prices skyrocketed so I am sure the same cost today would be much higher. By the way, i do not recommend shipping a roadster in an open carrier over that distance for obvious reasons.