I still have camera bodies from 10 years ago that I use. I don't really upgrade, I purchase tools and equipment based on ROI.
With ROI in mind I make more careful decisions and focus on camera bodies that can be upgraded, or that are high-end enough to produce for years. My last new camera body was two years ago, I'm unlikely to buy a new one for another year. I'd be more inclined to add lights, grip (light stands, soft boxes , etc.), lenses, upgrade software, color management and spend on marketing on a regular basis. Camera bodies are upgraded every few years or if I add a new photographer.
Can I make money on this is my first question, followed by "how long before this new camera, printer, lens is turning a profit?"
If it still is earning its keep and returning income it continues to be used. When something wears out, or stops being financially productive then I sell it or donate it.
It does not matter if it's a printer, camera, light, computer or other tool, it's got to earn its keep.