Deontay Wilder risks being "used as a dosser and a work man" if he does not demand equal pay for a fight with Anthony Joshua, says Tyson Fury.
Joshua, 28, holds the WBA, IBF and WBO titles and talks are continuing for him to face WBC title holder Wilder, 32.
Wilder has offered Joshua $50m (£37.2m) to fight in the United States, but the Briton wants the bout on home soil.
"If they are not going to take $50m, how much do they want?" said former world heavyweight champion Fury.
"There are people out there who haven't got bread to eat, never mind $50m."
Joshua previously said he wanted to "see the money" before agreeing to Wilder's offer of a fight "in either London or Vegas".
And the Briton's promoter, Eddie Hearn, has said he is hoping for clarity on the widely-anticipated bout "this week".
"Wilder deserves an equal right in that fight and if he doesn't get it he is being used as a dosser and a work man," Fury said in an interview with IFL TV.
"It shouldn't be about the money at that stage. They all have a few quid. They will get a lot of money. Why try and rip someone off with 'I'm the A side' and 'you're the B side'.
"They are both undefeated world champions, fight one another, 50-50 split, may the best man win and take all the belts."
Unbeaten Joshua has won all 21 of his professional fights, 20 by knockout, and added the WBO belt to his collection after a unanimous points win over Joseph Parker in Cardiff on 1 April.
Wilder beat Luis Ortiz in his last fight in March.
No heavyweight has ever held all four recognised world titles, meaning any Joshua-Wilder bout would be a likely box office hit regardless of which side of the Atlantic it was staged.
"All the big fights, if you want to be big time, every great fighter in this country has had to go to America and beat the Americans," said Fury, who will return to the ring after 924 days when he faces Sefer Seferi in Manchester on Saturday.
"Even singers want to go over and conquer America. If you can crack it you're in. The Spice Girls were big in England but they had to go and break America."