Adopting a pet will save a pet's life. The number one reason to adopt a pet is that you will be saving his life. Many shelters are overflowing with dogs and cats, they sometimes have to turn away animals simply because they do not have enough room. So when you adopt your pet, another one can take his place. The benefits of adopting a pet from a shelter are numerous, cost being a big one. Most humane societies and rescue organizations will charge $100-$400 for a pet. With that, you will get a dog that is completely up-to-date on vaccinations, spayed/neutered, and sometimes even micro-chipped .