Be sure to give your estimator as much information as you can in order to keep your cost as close to your estimate as possible.

Keep in mind that the estimator assumes, in every situation, the following:

You will not need additional supplies/packing materials to be provided by the mover.
You will have packed everything yourself that you had anticipated.
The scope of the work does not change markedly on the day of the move. In other words, you didn’t forget to tell the estimator about important (and heavy) stuff, such as:
The lawnmower your neighbor borrowed from you.
The unknown contents of your filled storage space.
The “priceless” junk in the basement you found under the tarp-the stuff that your wife was hoping would be left behind “by accident.”
Traffic from your old home to your new will not be worse than usual.