I'm restoring old implements as a hobby. I do have a big garden so they do get used. It's real easy to put more $ in them that they will ever bring.
I have a 72 GMC C20 work truck that I've repaired again and again. Every time I think I should just replace it the replacement cost is far more that the repair. Then I have way more in it than what it's worth so I feel the need to work it some more.