floyd mayweather and manny pacquiao meet on may 2 in las vegas .
tickets for the weigh-in went on sale on friday at 3 pm .
the mgm resorts box office was overwhelmed with calls for tickets .
between 500 and 1000 tickets for the may 2 mega-fight were snapped up in seconds when they went on sale on thursday night .
one ticket later appeared on stubhub priced at $ 128,705 -lrb- £ 85,508 -rrb- .