Might be an American thing? My parents spent about 1 month worth of my dad's salary on two wedding rings a long time ago. My dad actually wanted to buy a far more expensive ring for my mom, but she insisted to keep it simple and "cheap" and "unproblematic" to wear. Same story in the rest of the family.
Friends (usually a lot younger than my parents) spend even less on rings, I'd estimate 400-600 EUR per ring from what I keep hearing.
I've heard about that two months rule before, in American TV shows and movies, never thought about it. Now I wonder if it's really an American thing, or if people around me are just cheapskates :P