1 Wood is the most traditional, common and easily available material for decks; it is typically easier to work with than composite materials. 2  Composite deck installation can cost $25-$70 or more a square foot (8,000 -$22,400 for 16'x20).es, even a heart operation is and should be a known cost (approx. $100,000 today). So a deck should certainly be something that you can research materials/labor cost and DECIDE for yourself whether you feel the item is worth what its price.