Fiberglass entry doors are doors that are made of a composite material that mimics the appearance and feel of wood. They are durable, energy-efficient, and low-maintenance. The prices of fiberglass entry doors vary depending on the size, style, finish, and features of the door. A basic fiberglass door slab can cost as low as $150, while a prehung, wood-grained, and stained door with lights and panels can cost up to $7,000 or more. The average cost of a high-quality fiberglass entry door is $1,500 to $2,500, plus $400 to $800 for installation. ^{thisoldhouse.com 1 2}