Also look at any local hydraulic supply houses--they may scrap stuff that comes in. That is borrowed knowledge, however--nobody does stuff like that around here. The only industry in these parts is making rules you guys hate
But truth to tell, most places like that are under strict local do-gooder laws that prevent people from scrounging. Getting that permission requires a high level of trust, and there just isn't a lot of that going around these days.
I'm friends with a local fabricator, who will buy stuff for me when I ask him to. But he's been in the local crowd since his school days, and so has my wife, and I also send him work whenever I can. That said, the amount of material I've needed from him has been negligible from his perspective.
I've looked at the online sources, and they are spendy, particularly with shipping charges. The secret seems to be out about hobbyist fabricators.
Rick "following this thread" Denney