Last summer, I sold a Bellcrown pony-sized cart. Luckily, these carts 'break down' for easier shipping. The buyer, who was in Spokane, contacted one of those "mail it" places in Albuquerque; I disassembled the cart and took it into town to them. They were able to pack it for shipping, then it went freight via a company(I think it was ABF, because they had terminals both in Albuquerque and Spokane.) It got there just fine, well-packed-I don't know what it all cost her, however. A horse hauler might be able to bring it, too. You would want it to be protected, though-and not be being moved in and out of the hauling vehicle along the way.
Nearly two years ago, I ordered a road cart from Pequea Carriage in PA-was fortunate that the builder knew a woman who went across country with an 8 horse gooseneck, to buy Standardbreds OT in CA and bring them back to the east coast to sell. She would head west with a trailer load of carriages, then back with the horses. Luckily for me, she drove the 'southern' route(I-40) that trip; I met her just off the Interstate near my home-it cost me only $100 for the shipping!!
The last Jerald I got, a very small obstacle cart, cost @ $135 in shipping, picked up at the truck terminal-but that was around 6-8 years ago! (Jerald show carts DON'T 'break down' for shipping, and have to be VERY well-packed(and are!) for shipping--but that's got to make the cost higher than for a cart that can be 'compacted' into a square pkg. by being able to be taken apart somewhat.