It depends on whether you are buying for the main door or room door. The average supplier cost of a door would range from $150 to $350, depending on whether it is pre-hung or slab. On the other hand, the average cost for exterior doors ranges from $250 to $800, while high-end custom ones cost around $5,000 or more. It is important to note that exterior doors would need more framing, flashing, and load-bearing headers, leading to an overall increase in installation costs. The total installation costs from $360 to $1,150. The average cost for replacing bedroom or home main doors ranges from $100 to $300 for labour, with the door costs ranging from $50 to $500.