I don't aim to be a collector, but people find out you use film still, and give them to you. Or I find them at liquidation auctions for like $15-20 for a fine slr with a great clean prime lens, and am unable to say no.
I always check them out, shoot a few rolls, and then work on selling them as functional cameras at swap meets.
If they are flaky on the electronics side, or missing obvoius parts but otherwise the remaining bits look presentable, they get cataloged ( a use that I have for a digital p&s) and then tossed gently into a box in the garage attic. These become my working spare parts supplies. If they have not been called on for a few years, then these parts cameras get discarded.
Plastic point and shoot cameras with some adjustments might get kept, if the batteries are not missing or too expensive. Fixed focus el cheapo P&S cameras almost always get tossed. The found film in them is always a lot of fun to process and invariably I seem to get picture of other peoples cats and grandchildren.