First of all, it depends how broke you are, and how much money you’re turning down. Obviously. If you’re broke and someone is offering you money to write a screenplay, then do it. Nothing else to say.
I was broke when I adapted my first book, Fever Pitch, for the original UK version of the movie. Or rather, I wasn’t financially secure, by any means. When I started the process, I had a very young son who turned out to have incredibly complex health needs, and was already causing alarm and confusion. (As it turns out, he will need financial support for the rest of his life.) I had just taken out a mortgage on my first house. I had no idea whether the success of the book was repeatable in any way. It was a memoir, and I didn’t have another memoir in me. Not back then. And though I had started my first novel, I didn’t know whether I would finish it, or whether it was publishable, or whether anyone would read it.