My offers for stem PhD programs at ivy-type private research institutions were about 30k, one was more like 35k. At university of California schools, the stipend was more like 19k (and a higher cost of living). My current stipend is the standard here and not due to unusual scholarships or grant money. We're supposed to ask permission for outside work, but the department will actively help you find people to tutor.
Humanities grad students have a _much_ worse deal than STEM ones, typically.
From what I've seen, for STEM, the assumption is that your tuition is covered, you get a stipend that you can actually live on, your medical insurance is covered. For humanities, the working assumption is that none of that is true, and if some of it happens to be true, you're in luck.
Oh, and the humanities degrees often take longer too.
I worked for a physics professor at an ivy league school, not as a grad student, but as a software engineer on his team. I was working on a project with a database that contained all the personnel information -- everyone was getting between $30 and $35k.