I own multiple cameras but the cheapest one is probably is my Zenit 11, which I bought for 15 Euro and I load it with all kinds of 35 mm films, especially the Agfa APX 100.
What I love about using minimal photography equipment is the straight away and unpretentious handling. It's easy to take the camera with me anywhere, and I'm getting amazing results most of the time.
What I would say to those people who wanted to do photography in the simplest way possible is for them to never hesitate to take a picture, just try it out, use double or triple exposure and stay awake and alert for unconventional results.
In addition, stay tune to the changing conditions of the light, make use of it and don’t try to think of projects in such an organized kind of way. Meaning just take chances and always have the camera with you during those moments.