You didn't need wealth to avoid Vietnam as plenty of my friends joined the National Guard to avoid Vietnam. Or they went to Harvard Square and bought for $50 a letter from a doctor that you wet the bed and for and additional $75 your could also get a letter that you had nightmares. If you got drafted as I did after college all one had to do was take those letters and when they asked right before taking a test if anyone had nightmares or wet the bed or letters from their doctors to stand on one side of the room. About 25% of the kids stood on that side and didn't have to take the test. I was shocked as my neighbor had two letters. I had a bad knee from playing football and they gave me 6 months to have it operated on or they would do it for me. The doctor said it would be good practice for their young doctors. They never called me back. Four kids from my HS class died in Vietnam.
Years later my business partner's parents fled Vietnam in 1975 when he was 2 and made a wonderful life here. Each one of their children were either doctors, lawyers, or business professionals who were very successful.