Discard or not

[West Valley G]

Generally speaking am wondering how you all make decisions on repairing
things or just throwing them out. I am talking mainly about small engines
in general. I don't believe there are enough CC in Montana to even keep
a guy busy. I am a guy who owns all kinds of small engines and always want
every one of them to be running and work towards that end.
That being said, I also run across freebies from friends and enjoy tearing
em down, always want to fix them and that doesn't seem like a good idea
either. How do you decide what to keep and what to throw away. Even
if I am just going to part things out, what has value? A set of rings from
Model x, connecting rod from model z? The one thing I always keep are
nuts and bolts because every time I go to the hardware store they are more
expensive then last week. Am a bit of a neat freak so am working on how
to organize what I do keep. Love this forum and check it out every day
so thought I would see what you thought. Plus the shop is 20 degrees
so I have some time on my hands. Thanks Ken