Reminded me of this old article about profiting by sniping the most valuable books being deaccessioned: http://www.slate.com/articles/arts/culturebox/2010/10/confes...
I had the bright idea a few years back to give this a try. I went to a couple of library sales, scanning books and eyeballing others. I came away with a few books that I could have made a 5-10 dollar profit on. But I came away with something more valuable than that.
I looked at the other people at the sale doing the same thing I was, because there were several of them. Call me prejudiced, but here was my take. They seemed like older, retired guys who were probably earning a pension or collecting social security, and basically out and about doing this "job" just so that they could have an ostensible reason to escape the "Eye of Sauron" (read: wife).
None of them looked like they were making a living. They looked like they just wanted out of the house.