Make sure you arent dealing with a scammer. That is typical scam to sell a tractor cheap and then say they will pay for shipping also. There was a scam a while back where the seller only wanted to use a specific trucking outfit and they actually existed, but the tractor didnt and he took an escrow account like PayPal but it wasnt paypal. Anyway the scammer had some way to get your money from them without delivery of equipment. BEWARE.
Shipping via legal shippers will run you about $2 per mile, maybe less if they can pick up additional cargo each way. Expect to pay minimum of $1.50 per mile one way charge. If it were me and I had the time and a truck, I would buy my own trailer for $1500-1750 and haul it myself. 16 foot tandem axle trailers with brakes can be bought in Houston Texas area for as little as $1750 new. Put the money I would pay for shipping into something that I would have in my equipment inventory which may be more outlay, but at least I would have something to show for my $$$$.