Hi -- Thank you for writing this! I'm a person who is familiar with the broad strokes of consequentialism, but I've never read any Singer and I've never seen the arithmetic laid out as plainly you've done in this blog post. First, I'll describe what I think your reasoning is, and then, fully acknowledging that I might not understand your argument very well, I'll end with a little critique. Anyone can pile onto either part, by saying that I completely missed the point of your argument, or by pointing out flaws in my own reasoning.
When I was reading your post, I got a bit lost when you switched from counting life years to counting dollars. I'm going to reduce the problem to a hypothetical person who eats 1/8 of a pig every year but otherwise only eats plants, and like you, this person values the life of a pig at 1% of that of a person. If this person decided to give up eating pig meat, he or she would save the life of 1/8 of a pig per year, or equivalently 1/800 of a person per year. We want to put a price on sacrifice that our pig eater made by giving up meat, and we do that by saying that saving the life of a person costs $100. Compare that to saving 1/800 of a person by giving up pig meat, and we get $0.12. And we conclude that the inconvenience and the diminished pleasure that you would experience would be worth far more than 12 cents.
Do I have that right?
If I do, I guess I think that these incommensurates are harder to compare than the argument allows. It reminds me of the order of magnitude estimates for the likelihood of the existence of alien life in the universe. Usually, you'll see scientists using Drake's equation to argue that it's extremely likely that alien life is out there somewhere, but occasionally you'll see a creationist use exactly the same kind of reasoning, with different parameters and different magnitudes, to show how likely it is that life on Earth is unique. Meanwhile, Goldilocks planets are discovered, the amount of matter in the universe changes by a factor of 10, nuclear arsenals are stockpiled and pandemics sweep over the planet, and none of that can be accounted for by the order of magnitude argument.
I'm not able to simplify the issue, unfortunately. For me, it's a mixture of ethical concerns, for animals, the Earth, and perhaps ultimately human health and well being.
On the other hand, for me, the take away from the story you wrote is that pig lives and human lives are at stake when we make decisions as a society. I find both ends of the argument instructive -- pigs are harmed when we farm them inhumanely, but at the same time one shouldn't overstate the value of saving pigs, as it can't really be compared to saving the life of a person.