The average cost of door installation in your home depends upon the type of door, whether it’s an interior or exterior door and if the door frame is required or not. The average cost varies but can be around $425 for an interior door and upto $3000 or more for a standard exterior door.

The factors that affect the door installation cost include:

1. Door Type: The cost of the door could vary depending upon if it’s a regular, entry, patio or sliding door. Doors at the main entrance usually cost the most. 
2. Single or Double doors: A double door costs more than a single entry door however it provides more space at the entry.
3. Exterior or Interior: Generally, exterior doors cost more than interior doors. Exterior doors usually have glass and side lights that add to the cost of the door. A standard interior door with no glass is usually the most cost effective. 
4. Regular or Fire Rated Door: A fire rated door costs much more than a non fire rated door. These doors are usually installed at basement entrances or to separate one floor from another. 
5. Door Frame: A door frame will add to the cost of door installation. 
6. Door Hardware: Smart hardware like locks are more expensive compared to standard hardware although there are numerous advantages of Smart locks. 
7. Labour: Larger contractors charge more for door installation. You can consider hiring a handyman or a smaller contractor for the best installation rates.

Check out stores like Home Depot or Lowes to get an idea of their door collection. They have all kinds of doors including metal, glass, fibreglass & wooden doors.

Finally, if you are building an expensive home, you could consider custom doors, which cost much more than the standard ones but can add aesthetic value to your home renovation project. 

Your location may also dictate how much your door installation could cost. Some large cities are more expensive and the labour there charges much more compared to a less expensive city.