I’d say since the local cost is the same, then the price difference must be attributable to the fact that Uhaul needs trucks in San Diego more than Dallas.
Probably caused by higher net outflow of trucks from San Diego.
Could be a spike in San Diego demand for local moves, but I doubt it.
Maybe there is some difference in the cost of doing business, but I doubt it accounts for a 2x rate difference here.
I think it’s probably a pretty good sniff test for the “self move” crowd. Probably contractors looking for a better market.