A dog is free, they are all over, you can even get a collar, leash, bag of food and spay neuter included in the package, which is free. That said I paid $40.00 for all of that when I adopted my last dog from a shelter. You are correct in that vet bills can add up, and in fact this is the only thing on the chart that is rational in my opinion. The other thing, that the chart does not factor in, is the value and companionship of a good friend, which if a value could be put on this, would be in the several hundred million dollar range.
Love is the way.