Yup. Amsterdam to Boston on … gosh was it Pan Am, or TWA, or some other airline that doesn’t exist any more? They were promoting their new route with an inaugural fare of just $50.
It was 1978 and I had graduated from college and was bumming around Europe on an Interail Pass. I started in London (thanks to Freddie Laker) and over a period of five months had made my way down to Greece and was heading back North. I was backpacking and staying in youth hostels and having a great time.