I bought my F3 new because it was the least expensive Nikon to own. With the occasional cleaning and calibration, it was good for 500,000 to a million shots. It was a primary source of revenue, so if it broke on a shoot, not only would I lose the shoot but probably the client. That I could not afford. I still have it, though it has been many years since I used it. I could have bought cheaper, but reliability and longevity were the primary considerations, with versatility a close second. Buying bottom of the line bodies, I would have worn out many at a cost way beyond one F3.
Totally out of touch with used film-camera prices, I checked KEH camera brokers and B&H—the largest camera store in the world—in the USA. Interestingly, the difference in price between consumer-level cameras and top of the line pro cameras in excellent condition is minimal. Since these are used cameras, I would certainly pay the difference for the more robust. A well taken care of consumer-level camera may be cosmetically perfect, but ready for an expensive repair simply due to wear.