A single-signed Lou Brock baseball is worth $50-$85. A autographed portrait of Lou Brock is worth around $35. Other items may be worth more or less. Brock's signature can be found on the front of the baseball, which is signed in black sharpie. The baseball was played during Brock's era (1972-1991), but it is not certified by Major League Baseball and is therefore not considered legal for sale or use. In 2007, an unauthenticated Brock baseball sold at auction for $40,000. In 2008, another unauthenticated Brock baseball sold for $60,000. Both were reported to have been given to Brock when he was with the St. Louis Cardinals. An authenticated Brock baseball is worth more because it has the certificate of authenticity from MLB. An authenticated Brock baseball sold at auction in 2011 brought in $110,000. Brock's son, Luke, who now plays first base for the Arizona Diamondbacks, is also a famous baseball player. His autograph is worth $30. Other people's autographs are usually worth less than this because they are not well known. An unautographed baseball is worth nothing.