cats

Not really. I adopted a stray kitten which cost 0$, a couple of vet visits set me back maybe 200$ for most of his life. Cat food isn't expensive, car toys, and the environment was easy to supply and make it interesting. Later in life he got a tumor, and regular vet visits did cost a couple of thousand bucks and he eventually had to be put to sleep. But that was the most amazing cat, who gave happiness and love to 4 people, and a kitty friend.