Anyone willing to spring for the price of a Coke and burger.

[Vladv1]

"It could be soul-destroying, knowing none of the audience were there specifically to see you, whether they turned up or not. Money was tight and they got used to cadging drinks where they could, and living off the goodwill of "anyone willing to spring for the price of a Coke and burger".
Mick Wall, "Hell Ain't A Bad Place To Be".

Could you please reword the bolded-can't get it at all.

 

[teechar]

Here, "spring for" means pay for.
From the Cambridge Dictionary:
"US informal
to pay for or buy something, often for someone else"

spring for something

1. to pay for or buy something, often for someone else: 2. to pay for or buy…

dictionary.cambridge.org

 

[SoothingDave]

They mooched food.