Originally Posted by Tallulah
Financially I suppose a PhD leaves you without debt compared to a masters which you pay for. But then look at the opportunity cost if you take more than three years to do it.
There is more funding for research assistantships in the sciences than the humanities, and a substantial fraction of humanities graduate students are taking on substantial debt:

http://chronicle.com/article/Graduate-School-in-the/44846
Chronicle of Higher Education
January 30, 2009
Graduate School in the Humanities: Just Don't Go
By Thomas H. Benton

Quote
Meanwhile, more and more students are flattered to find themselves admitted to graduate programs; many are taking on considerable debt to do so. According to the Humanities Indicators Project of the American Academy of Arts and Sciences, about 23 percent of humanities students end up owing more than $30,000, and more than 14 percent owe more than $50,000.
I think the whole article is worth reading for prospective graduate students and people who care about them.