When i was running around the country back in 2010 to 2015 picking up tractors and such, I would keep an eye on the hauling forum on Yesterday's tractors. I could find a load going towards where I wanted to go, and my standard price was a dollar a loaded mile. That was usually enough to pay my fuel round trip, which was what I was after. Every now and then I would find a second load to go with my first, at which point I would make money hauling. You have to trust people a little to be able to do this, as I could have walked off with whatever I was hauling, or worse. They could have refused to pay me when I got there, but I always collected when I arrived, no money up front, and the load wasn't coming off the trailer till it was paid for. I never had an issue, but there is room for some. Only one person ever even joked about paying me less than I had negotiated.
Depending on how fast you need it hauled will determine how much it will cost you. Got time to wait for someone who "is going that way" and you might save a little money. The general nature of how freight moves will also have bearing on what it costs you. If your tractor was in south Florida and needed to go to Atlanta, you could get it moved cheap. The other way around would cost you double.
David from jax