There is no market for your proposed trade. In this case using money as a proxy for utility/preference doesn't net you any insight because you can't exchange vegetarianism or animal-years-of-torture for anything else. Of course you can convert to dollars if you really want to, but you have to convert both sides - how much would you have to be paid to allow an animal to be tortured for three days? (This is equivalent to the original question, we've just gone through some unnecessary conversions).