Wow! Congratulations BlueCrustacean! How awesome... I'd love to be able to do freelance work within the film industry, that just sounds so cool. I'm a little envious.

No good tips here. Maybe your best bet is to get on a forum for others doing the same kind of work, and ask for advice on how much you should be charging based on the project, your location, and your experience? That way, you can go in with a reasonable number and know what to expect?

I agree that you should be paid, but also... usually it's good to agree on the pay before you accept the job (which I'm sure you know). In this case though, I really do think the experience could help make up for it... it's your first freelance industry job! That means you'll hopefully be learning a ton, get your name out there, get a good reference, increase your confidence... all things that should lead to more work and even better pay in the future.

"I don't know, maybe I was too impatient about it, but at least I planted the suggestion there. They say it's unlikely for freelancers to get paid without asking for it first." - I've looked into freelancing in my industry, and my understanding is that as a freelancer, you'd never take a job without first agreeing to how much you're being paid. You still might struggle with being paid (I hear that most clients are slow to pay the bills and trying to collect can be frustrating), but it really is something that, at least in the area where I work, you wouldn't start working until you agreed on a price. Not sure if it works the same way for the type of work you're doing?

Good luck. I hope it goes well, that you get paid fairly, enjoy the work, and make some good contacts for future work!