Questions of liability and other coverage is paramount. Experience also matters. The trailer needs to be ready to travel (tires, bearings, brakes, wiring, lighting, safety chains, breakaway switch, etc) before the driver hooks up. If it isn't being towed on the ground then trailer condition is moot, overall.
My last quote by an experienced RV hauler was in Jan '09 at $1.25/mile, zip code to zip code, on the ground. With the quote above, it certainly won't be lower than the one I had (which pays the truck, but not the driver) as a range. I'd rather have it placed on a trailer than trust to components I haven't inspected & corrected which is more expensive, likely, but removes all concerns about trailer condition.
1990 35' Silver Streak Sterling
; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 10-cpm solo, 18-cpm towing
Sold: Silver Streak Model 3411