What is the fine-grained topic of the following text: Some of the Ferrell signed cards, by the way, have sold for around $2,000 with buyback autos of Ken Griffey Jr., Nolan Ryan, Chipper Jones and Ozzie Smith also bringing several hundred dollars each and, of course, the Kris Bryant auto redemptions have been strong sellers. Only return the topic.
Value and sales of specific signed baseball cards