[Ennis hitches a ride to a job, and saves half a cigarette, while Jack has a junky truck.]
The film's opening scenes emphasize the poor economy of the time. These men have to struggle and two tough jobs simply to survive.
AGUIRRE: If you two pair of deuces are lookin' for work, I suggest you get your scrawny asses in here pronto
Aguirre hires the men without so much as an interview. Them simply showing up is good enough for him. We have a feeling he can't be paying them all that much, if he accepts them at first sight.
JACK: Money's a good point.
Jack does the rodeo not because he enjoys it, but because it earns him money. Men have to do things they don't want to do. You could say the same thing about Jack's marriage.
JACK: Well, I can spare you a loan, bud, if you're short on cash. Give it to you when we get to Signal.
ENNIS: I don't need your money. You know, I ain't in the poorhouse. S***!
Ennis is proud, which is a masculine trait, and his pride won't let him be in Jack Twist's debt.
ENNIS: Jack, I gotta work. Huh? In them earlier days I just quit the job. You forget what it's like bein' broke all the time. You ever hear of child support? I'll tell you this, I can't quit this one. And I can't get the time off. It was hard enough gettin' this time. The tradeoff was August. You got a better idea?
Ennis isn't lying here, so you could argue that one reason Jack and Ennis's relationship deteriorates isn't because of Ennis's latent homophobia, but because of his poverty. However, that argument's flawed, because if Ennis moved in with Jack, Jack's money would keep them financially secure.