How to determine compensation for developing new course for community college?
I think you're going to find that they want to pay you their adjunct rate for teaching the course, which might be $3,000 or so.  If you want to be paid more, you will probably need to negotiate a list of deliverables, which would then allow someone else to teach the course next time.

I believe there are two motivations for being an adjunct instructor.  Some people make a living at it by piecing together adjunct appointments from two or more institutions.  Others do it for the love of teaching; they have to have day jobs to support their teaching hobby.  I got paid about $2,500 to develop and teach a course in web applications in 1997.  Now I am retired from the day job I had then, have a full-time faculty appointment, an office at school, and everything!

Edited to add: I missed that it is a community education course.  You might get a few bucks more for that, or extra pay for classes over a certain size.  It will still be a four-figure amount.