It's better to have a rough estimate of the expenses, even if you are thinking of hiring professional movers. It will help you in negotiating the right price with these firms. These companies will provide their own estimation; still you can save some money by doing your own calculation and then comparing it with the quotes provided by movers. In case, they are asking for a price higher than what you deem reasonable, you can think of screwing up your courage and going for the job yourself.