system
Given the following post, respond as if you're commenting on Reddit:
human
Firefly : Does Shepherd Book have to keep paying to stay on Serenity throughout the series...

... while watching Out of Gas I noticed Mal tell Inara she was paid up until the end of the month, understandable, she runs a business out of the shuttle.

But those not in the crew (River, Simon, Book), would they still have to pay? I think Simon's medical skills cover him and River... does that mean Book is the only one having to pay to stay on Serenity? He steers clear of all their jobs (bar rescuing Mal from Niska, arguably not a "job"), so do you think he's given the benefit of the doubt as he's a Shepherd? Thoughts?

Answers on a post card....
gpt
Inara pays because she is a customer. She's not paying for passage aboard Serenity, she's paying to rent out the shuttle. Everyone else is more like an employee, they work for room, board, and a cut of the loot.

Simon and Shepherd started out as paying passengers, but ended up part of the crew. Like the rest of the crew, they don't pay to stay, they offer whatever services they can.