Floyd Mayweather and Manny Pacquiao's fight sold out within minutes and tickets immediately appeared on websites for as much as 95 thousand dollars.
Only 1,000 tickets were made available to the public for the fight on May 2nd at the MGM Grand in Las Vegas.
The remaining 15,500 seats will go to fighters, sponsors and promoters.
The cheapest ticket for the bout cost 2 thousand dollars, rising to about 10 thousand.
The contest between the two has been set since February, but a ticket contract was only finalised this week.
Tickets officially went on sale on today, but within minutes they appeared on sites such as StubHub - an online marketplace owned by eBay - with the cheapest priced at 7 thousand dollars.
38-year-old American Mayweather and 36-year-old Filipino Pacquiao are considered two of the best fighters of their generation and the bout, which has been in the pipeline for five years, is set to generate 320 million dollars.
Mayweather has won all 47 of his fights, 26 by knockout, while Pacquiao has a record of 57 wins, five losses and two draws.