At one vintage paper fair I went to I found what I figured out was a late 1960s sportswriter's photo archive. It was a banker box full of material. The dealer sold me a bunch of mixed stuff for a few bucks an item. They are some of my favorite sports photos, including this one:
For those of you not familiar with the subjects, that's Wilt Chamberlain handling the ball with Bill Russell coming in to defend and Bob Cousy behind him, taken in 1961. I also found this:
An ABA Minnesota Pipers 1968 team issue of Connie Hawkins. It is a 4 x 5 card (not photo, it is printed). Last one I saw, which was several years ago, sold for $350.