$3.15 an hour was $6552 a year. It was probably a going wage and pretty stable, but the machinist would have been working on Department of Defense production for the Viet Nam war and subject to political harassment and instability.
In 1967, my wife and I bought a brand new 1967 Pontiac Firebird, newest & hottest car on the market, for $3700, including all the sales taxes & other charges. We bought it in Syracuse, NY, and we were able to pay cash. We paid $90 a month in rent and another $90 a month for heating oil. I was going to college on the GI Bill, had a part-time job as an instrument tech working on a wind tunnel. My wife had just finished her MBA and was a junior officer in a big bank. Our income for that year was $11,000. Most of that was my wife’s salary, but $3600 of it was the GI Bill. All that was before kids.