A poorly lit green screen with bad quality footage could easily take a very long time to correct depending on what it's footage of, how bad it is, the background that's supposed to be getting put behind it, and how good of a finished job it needs to be. A full-on professional keying job, even on a well-lit greenscreen can easily take more than 20 minutes to do (again, depending on a lot of factors).
That being said, here's a link to a jobs posting forum for little jobs like this. Also, I would be willing to take a look at it once I'm done with my day job and get home, if nobody else is interested.
Did you get any help with your greenscreen project?
Let me know if you still need help... I have tons of green-screen experience, but I'll have to see your footage before I can make any promises!
My minimum is a day.
Your explanation sounds like this is a hand-tweaked rotoscoping project. Could take three days. I will pass.