Advice?

[nomirena]

I was just asked by a professor here to do some freelance editing of three articles presented at a symposium and an addendum. The whole thing will be published with images in one volume. I'm not sure how much to charge per hour. Does anyone have any experience with this? I've done a lot of editing in my 5 yrs at this job, at least 10 catalogues.

Any advice is greatly appreciated. Thanks.