That's because all of the other articles you're referencing just repeated the announced figure. Whereas the true figures come from the actual tax returns filed for the event. Are you accusing Bob Arum of tax fraud?
I believe 60k is a more real figure for this fight, but it can make 70k or even more depending on the undercard.
ticket prices are priced right, and the Dallas Metroplex is a huge, huge area of people that are not only boxing fans but of fans of Margacheato, it sould fare really well, given it has all the elements to be successful