Explain the paycheck deal

In episode 4, the mobsters implement a plan where the manager of a construction site should get their paycheck on Friday, when the banks are closed.
So they have to wait til Monday to cash the check at the bank.
But they are given the option to get cash immediately on Friday, for a 5% fee.

Was this a plausible scenario?

1. Isn't Friday the usual payday? Why did they make it out to be so unusual? I thought everyone traditionally got paid on Fridays.
2. It's a pretty hefty fee. 5% just to get your money 2.5 days early.
Were construction workers in the 70s really that desperate for money?
Didn't most people have at least enough money saved to last them through a weekend?
3. Even if they were low on cash - didn't people have checkbooks for this very reason? They could buy stuff with a check on a friday, and the check wouldn't clear until monday - thus it wouldn't matter if their bank account was empty during the weekend, as long as it was filled up on monday morning.