As of 2010, you may pay 70 cents per lineal foot for 2 by 6-inch pressure-treated pine to more than $5 per foot for 6-inch hardwood Most composite decking made with PVC plastic sells for $1 to $3 per foot. Add in $400 for framing lumber, cement and hardware, and your project may run $620 to $2,400 or more..
As of 2010, licensed building contractors in the United States are typically charging from $20 to $50 per square foot of decking installed. Therefore, expect to pay a contractor $4,000 to $10,000 for most 10 by 20-foot decks, materials included.
Deck costs vary considerably depending on region, site conditions, local building standards, design, materials and labor. Because each deck is different, the only way to determine what your project should cost is to research your options thoroughly.