Jay Z Hosting Mayweather/Pacquiao Party

The competition for the hottest Mayweather/Pacquiao post-fight party is over ... cause Jay Z just announced he's getting in the game ... with V.I.P. tables running up to $50k-a-pop.

It's all going down at Marquee nightclub at the Cosmopolitan Hotel in Vegas -- just down the way from where Manny and Floyd will be facing off on May 2nd.

 TMZ spoke with party honchos who tell us they expect this to be the biggest after-party on the strip -- despite fierce competition from stars like Nicki Minaj, Chris Brown and 2 Chainz.

If you don't have $50k, don't worry ... there are cheaper options. 

General admission tickets are $100 

Tickets for females are significantly cheaper ... $30. 

Gender equality -- it ain't for everybody.