I just found this out today and thought it was worth sharing. Habitat for Humanity has recently opened 3 Home Centers here in SA, where they sell building materials, flooring, area carpets, kitchen and bathroom cabinets and furniture donated by builders and building supply companies at reduced prices. (If you don't live in SA checkout the national website and put in your zip code for locations near you.)
They can also resell building materials from your house. Habitat offers free deconstruction and tearout services for your remodeling project. The wrecking crew then salvages the materials and they are sold at the store. Plus, you can use it as a tax deduction!