Why are these two books by Emmanuel Todd so expensive?

The Causes of Progress: Culture, Authority, and Change (Family Sexuality and Social Relations in Past Times) by Emmanuel Todd and Richard Boulind (Jun 1987)

Formats		Price		New	Used
Hardcover					$71.95

Explanation of Ideology: Family Structures and Social Systems (Family, sexuality, and social relations in past... by Emmanuel Todd and D. Garrioch (Oct 3, 1985)

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Formats		Price		New	Used
Hardcover				$393.93	$190.17