A big worry of mine is that of cameras being pitched into the garbage because repairs are "too expensive" or because they can no longer be repaired.
In either of the above cases, I would send the old cameras to a camera repair technician to use for parts. I would be willing to pay for mailing to avoid these old cameras being lost forever in a landfill.
I'm willing to pay more for an older camera that has been serviced, as the value to me is what I will get out of it, not just its market value.
It distresses me to see statements online about it being cheaper to buy another used camera than to get one repaired, as this suggests the old one will be thrown out. By getting an old camera serviced or repaired, I know that I will have a fully functional tool. Buying another used one, I don't know that.
- Murray
This is a big fear of mine too. The thing you may be tossing out of cost might just be the incredibly rare part someone else has been searching for ages for.
This is definitely true for some of my hobbies, all of which seem to involve repairing old things (fountain pens, bicycles, Japanese watches—well, I don't do my own work on that last one). In my usual browsing antique and thrift shops for old pens, I can't tell you how many times I've heard from shopkeepers that when they get them in from estates, unless they're a prestige brand like Montblanc, they pull the nibs to sell for scrap gold and toss the bodies. (meanwhile, they'll have old Kodak Brownies on the shelf going for $100)
They have no idea that some collectors will pay hundreds just to get them fixed up.
Another anecdote: there's a shop around here that I really adore that can best be described as a junk broker—they take in whatever you don't want and resell it for tinkerers, artists, kids craft projects, etc. A while back they put a call on social media looking for old optical gear to take apart for science kits or somesuch. Someone responded that they had their grandfather's old camera kit—and it was a very, very nice Olympus setup with quite a few fast primes.
I nearly had a heart attack and had to sit down for a second and remember there's plenty out there left.
It's like enlargers and darkroom equipment. You hardly find them new, but people getting rid of them can't give them away.