Bennett said it all. I think it's especially important to recognize that Lomax's money from copyright was most of the money he could ever expect to get, and it wasn't that much. He got what the underfunded LoC department could afford, got some University grants, and paid the rest himself. He collected because he was compelled to, certainly not because he thought he'd get rich!
Also, anyone who can paint him as a racist
1) never met him
2) never read his books
I've done both, and he was more introspective about his own position vis-a-vis race than most of us. Beyond that, he put his money, his name and his ass on the line to show the world that, for example, the African-American musical tradition drew on rich cultural resources from Africa, an assertion that could have gotten him shot if the local sherriff heard him say it. Because of this, it's hard to interpret a lot of his public behavior. He was always conscious of how his public image might affect his future abilities to collect.
BTW, Armen, it's true that he sometimes put together corny pseudo-jook joints on stage at Newport, but this wasn't for paternalistic reasons. He wanted people to get a sense of what this tradition looked like. Is it more racist to assume that the delta bluseman will be able to handle this, or to assume he is "somewhat mystified" by it? Neither position can be proved without talking to the bluesman, which Lomax did and we didn't...