New York Times reports that a billion-user database was sold on the Dark Web last August for $300,000.

https://yro.slashdot.org/story/16/12/16/142233/yahoos-billion-user-database-reportedly-sold-on-the-dark-web-for-just-300000—nyt

http://thenextweb.com/security/2016/12/16/yahoos-billion-user-database-reportedly-sold-on-the-dark-web-for-just-300000/