I'm encouraged by groups like www.freecycle.com and local dumps with swapshops that encourage folks to re-use products that others discard. I've gotten lots of feast gear, pottery, clothes, power tools (surprisingly in good shape), and a variety of other things using both of these sources. I don't live near many dumpsters except for restaurants which tend to be rather dirty.
I especially encourage the freecycle groups. They're very addictive and you meet a lot of nice folks in the process.