Where do most rental companies buy all of this used gear I'm hearing about. They say Ebay (yes, OK I see it sometimes) and industry sources. What are these industry sources? Does anybody know of listings of offline auctions or inside sources, not only for cameras, but other gear as well. Just wondering if I'm missing something here.

Since they are working a lot with professional camera operators
and studios they are probably getting "stuff" through those
contacts, would be my guess...