My favorite places to find landscaping materials are through my local Freecycle group and Craigslist. People are constantly tossing out pavers, wood and planters and you can pick these up for free. We built six raised beds out of old cedar decking we received for free if we would just haul it all away. We also built a raised terrace by our driveway from discarded patio pavers. The extra pavers were used to create a border for our fruit trees and a retaining wall around a pond.