fans will be charged to watch a weigh-in for the first time when floyd mayweather and manny pacquaio step on the scales .
all profits will be donated to charities nominated by the boxers .
mayweather and pacquiao will be weighed at the grand garden arena .
wladimir klitschko admits that he is considering retirement .
the ukrainian looks set to fight tyson fury and deontay wilder .
carl froch may choose to retire after julio cesar chavez jnr 's defeat by andrzej fonfara .
froch had hoped to face the mexican in las vegas later this year .