"Little Black Sambo" by Helen Bannerman remains one of the children's classics most in demand, bringing $6000-$17000, depending on condition, for the 1899 edition. Reprints c. 1930s bring up to $1800. The original text, as well as a poorly thought out PC edition, are still in print.
A first of "Tintin au Congo," more recent and printed in large quantities, only sells for $500 or so. It remains in print in French and English.

Books reflect their period, and must be read in order to appreciate the society of our antecedents. No one is educated who fails to understand the society of our past and its literature. It is a severe fault of our educational system and our society that this is not taught to our young. Instead, apologists wring their hands, spread pap instead of knowledge and excuse anti-social behavior on the grounds that our forefathers were to blame for their present lowly condition.