Tickets have quietly gone on sale for the April 10 clash between former heavyweight champion Evander Holyfield and WBF titleholder Francois Botha at the Thomas and Mack Center in Las Vegas. Seats are $25, $75, $150 and $250. The 47-year-old ring legend Holyfield has previously fought in Las Vegas 16 times, the most recent being his bout with James Toney in 2003.