How much should someone expect to pay for writing a thesis?

If I am to research (conduct interviews for a Psychology thesis), and then write 50–60 pages of a Masters thesis, how much should I expect to get paid?

I’m being given about 6 weeks to complete the work, and have nothing more than a very bare outline to begin with. The first chapter of the thesis is already complete – I would be writing Chapters 2 & 3 (the remainder of the paper).