One day, several years ago, I came home to find my next door neighbor's cat on my front porch with a broken lower jaw and an eye hanging out. We picked him up and rushed him to the vet. The vet said he'd make it, the eye was destroyed so he'd be half-blind, but all the pieces of the lower jaw were there, so he'd set it, tube feed him for a couple days, and send him home. We got the expected bill, only about $200 if I remember, and told our neighbor as soon as he got home.
He said, "What!! I'm not paying that for any
cat. You should have left him, I'd have shot him when I got home."
So we acquired another cat.
As it happened, I was my neighbor's landlord. A couple years later, he told me he was going to adopt a puppy.
I promptly put an eviction notice on his door. When he came over all hot, I pointed at "Zipperhead," our new cat, and explained the terms of his lease. He gets a pet, he leaves.
He didn't get another pet as long as he lived there.
But there you go, I'm only a heartless, greedy, self-centered Repig...no way would I actually rescue someone else's pet.
{Oh, and BTW, the Scottie I lost a few months ago cost us over $500 before they did the scan that determined he was full of cancer. It's just what you do for animals...)