Yes cats are much cheaper than dogs to care for.
Cats require less food and the cat food is usually cheaper than dog food as well.
Cats are usually smaller than dogs especially if you compare a cat to a large dog.
The larger dog will require more food to eat per month than a small cat would need.
With a cat you can easily leave them home alone with water and food and go away for a few days or longer but with a dog you usually have to take the dog with you or hire a dog sitter or take the dog to a kennel while you're away.
Dogs require more grooming and medical care as well while cats do not need a lot of grooming and sometimes no grooming at all.
If you want to have a pet and need a cheaper pet then a cat is a good option.
Cats are also much easier to take care of and are much cleaner animals and quieter as well.
There's also no need to walk a cat like you would a dog.