Dr Quick wrote:
If you check towing laws in most states, 3,000 LBS is the most that you can tow with out brakes.
Again, that applies to TRAILERS, and the legal definition of a trailer often specifically excludes a towed motor vehicle.
U-Haul dollys are, IIRC, Demco Kar Kaddy dollys, built especially for U-Haul. They have surge brakes.
However, I agree, even though your trip is a one-time thing, you can probably find a good used dolly for much less than you would pay in rental charges over the long term.
A couple years ago, I paid $700 for a Kar Kaddy (without brakes), to tow my PT Cruiser from here to Ringgold GA and back. It worked just fine. I recently sold the dolly for $550.