Masters from UW-Madison here. Got it in 1987. Back then, I did pay tuition but it was super cheap, like $2400/year. The TA pay (I taught the intro to programming class) was about $16K/year for 2 semesters of teaching. It was just enough to live on.

I've got a kid going into math who wants a PhD. I'd love to see what that looks like for him at various good universities (maybe it's lower in the comments).