It's a very subjective opinion depending on so many things.
I racked up $140k debt on undergrad. My parents didn't pay for school, never gave me a dime for my books, brushes, fuel, or anything related to school whatsoever - and I never asked - I was on my own. But considering that when I was enrolling in undergrad and applying for aid, and they make a decent amount of money, there were a lot of grants/awards that I couldn't get, despite that they were not helping with tuition or supplies whatsoever. So I had to use loans for funding, and a $90k scholarship.
Without going into detail, that debt has been utterly debilitating since leaving school. I wouldn't wish it upon anyone. To spend that much money on an education / building skills/desire, and be crippled by it in the end (and unable to USE those skills as a result), is an awful situation to be in.
So, in my world, $100k will never be worth it again. I don't regret spending the money on undergrad, because I loved it and I wouldn't trade that education or community, nor the experiences I had, for the world, but I would have far done more to secure better financial assistance and done more internships/work experiences to help secure something beyond graduation. (I spent the entirety of my undergrad working 25-30hr/week tending bar, mucking stalls, doing whatever job I could, to afford supplies/fuel/etc and passed up all the good unpaid internships and work experiences that, while not paying then, would have helped me in the longer run.)
Branding and prestige aren't even on my radar. How much funding the school will offer and what sort of work opportunities (teaching assistantships, etc) are available are more important to me. I see postgrad as an opportunity to focus exclusively on developing your practice in a critical environment, and while faculty do matter, most things are what you make of them.
This article is well worth a read:
http://www.rawstory.com/rs/2015/01/this-college-instructor-has-a-masters-degree-and-shes-still-living-in-poverty/