The answer is it is her book
The word wealth meant about the lesson he learned.
In Schindler's List, Schindler tricks the Nazi Amon Goeth into helping him save Jewish prisoners from Auschwitz by pretending like he hates Jews and only wants them for cheap labor in his factory. In reality, his factory ensures they will live. Schindler buys the prisoners from Goeth, effectively sneaking them out from under his nose.
