If you hire someone to install the door it will cost from $1,000.00 to $5,000.00 depending on the style of door and how expensive the door is.
When I had a remodel company install a new front door and frame and the door was just the cheapest model it cost me $1,000.00 including the door, frame and removal of the old door and installation of the new door.
If you can find someone else to do the job you may get a cheaper cost to install the door but sometimes it pays to pay for quality work.