There shouldn't be any extra "add on" fees or anything like that if they're a legitimate company. You probably should allow for some variance depending on the distance and how much weight is being moved. Those are the main factors that affect cost as far as I know. I've used a US based company called A1 Auto Transport, Inc. and didn't have any problems or surprises. They gave me an estimate based on what I needed and the final tally was right around the number, if not a little under as I recall. Any mover worth their salt should do the same I would assume.