Fascinating to read this. I dabble a bit in the 'find & sell' process but not systematically. I live in a very rural area in the UK so haven't got the advantage of being in city for this. But the local rubbish dump is a very good source.

Also Freecycle is extremely good. I have had some excellent pickups from that including a wheelchair, a fruit cage, a pressure washer and a lawn mower. All working and all for free. Do you have Freecycle over your way?