My first freelance writing job was writing a short script for a commercial. It was a two-page script. The client guided me through the whole process and I got paid $30. Not bad for someone who was just getting into the freelance writing business. I did get 2 more gigs which paid $90 each soon after but I wouldn't do any more because the payment was too low.
I haven't done any script writing since then but if someone is willing to pay $5K for a 120 page re-write I'll do it. Otherwise I don't plan to write any more scripts in future.