Mayweather vs. Pacquiao -- Tickets Go On Sale ... TODAY!!!

Finally ... tickets to the Mayweather vs. Pacquiao fight are going on sale TODAY -- but you gotta move fast, because we're told there will only be 500 available to the public!

The tickets will go on sale on Ticketmaster at Noon PT -- starting at $1,500-a-pop and going all the way up to $7,500.

Promoters are limiting the amount of tickets per household to just 4.