Will adopting stray dogs bring good luck? Is it true that the old man said he would get rich?

Someone has calculated that the cost of finding a stray dog is no less than buying a breed of dog. So you can't eat and get vaccinated if you have a dog? Doesn't it cost money? Dogs can't be bought or compensated? Is it time to walk the dog and clean up? In that case, how can there be four or five thousand dollars a year? Maybe you have to change the rental house for the dog, or the landlord won't rent it. I'm afraid your income will stagnate. At that time, it will not bring good luck, but break the money!