Fiberglass swimming pools are slightly less expensive than concrete pools, usually ranging from $20,000 to $40,000, not including decking or patio. Again, optional features such as heaters, lights, slides and automatic pool covers will add to the total purchase price. A pool that is the same length but 6 feet deep with standard concrete decking, upgraded lighting and a diving board might cost $30,000 to $35,000. 2  A large pool-say 40 inches long and 6 feet deep-with a spa and heater, upgraded stamped concrete decking, upgraded lighting and a diving board might cost $50,000 or more.