The thread is about the price of meat and storing it, so it makes sense to consider how much protein is in the food and how much it costs. To not do so would be like saying, "We need to spend less money on a car. Should we get a cheap car? No, it's not red."
Well originally it was only about storing it, until you replied comparing prices, of course beans are cheaper. But the thread was about efficient long term storage.
But either way I recommend storing and buying both. Definitely not going on a crusade against beans, they're great! (and so is meat)
Another user recommended eggs if you're concerned about protein to price ratio, but it's harder to store efficiently without getting creative.
You could farm your own eggs as I do, but it requires a lot of space (and a love for chickens, they can be a hassle).
Also, see my response about "protein quality". https://news.ycombinator.com/item?id=32417603