MOVING ...Cheapest way to move across country?

Walk

Have you considered selling your stuff here and buying replacement stuff on the other side? It is about $0.60 per pound to move interstate, so that means a desk that weights 100 pounds will cost you $60 to move. If you could sell it for $20 and buy another used one for $40, you are better off.

The only thing you save when hiring someone to do it for you is time and the comfort of not having to load and unload it yourself. Since you're talking money here, the cheapest way is to do it yourself. You don't have much, and you'll probably only need the U-Haul for two or three days. You probably won't need much more than the smallest or second-smallest box truck they have. Eight hundred miles is hardly cross country, it's about 12hrs to drive.