Another anecdotal data point: When I married, I was working as a low-level reporter for near minimum wage. We married at a city courthouse and had a reception in the living room with my housemates who happened to be home at the time. I didn't buy a rock of any sort, though I gave her a plain gold wedding band I got from an estate sale. She gave me one she bought for $70 at a jewelry store.
That happened thirty years ago and we are still happily married with three kids, two of them in college right now and one in high school.