If you cannot afford to keep the animal you shouldn't have it. Sometimes animals have to be put down, but not using the logic you are using. Calculations like you are making are done by machines. Machines have no empathy and no soul if you believe in that sort of thing. No one needs the kind of math that you are doing. We are all aware of the calculations. It cost me less than I have paid for a snake to bring a human into this world. I can make humans for free. Does that mean the baby does not have value and I should just let it die rather than paying for a hospital visit when it gets sick?
You, whoever you are have a problem. Luckily I do not have to deal with it. I predict you will soon be gone from here.